Things i learn and wanna share

Connect PHP with Oracle database

me2blog — Sat, 18 Oct 2008 15:57:53 +0000

I spent the last four days looking for the correct way to Connect Apache server (PHP) with Oracle database, unfortunatly I didn’t find any complete article.So in this blog, I’m giving my expernce to connect ‘em 2geth

1. Install Apache server:

I make this step in a seprated blog page, plz check it from this link:Install Apache HTTP server

2. Extract the PHP zip folder:

1. Unzip the PHP file into c:\php

2. Copy all the files with the .dll extension to C:\WINDOS\system

3. Copy php5apache2.dll to C:\Apache\Apache2\modules

3. Copy the file php.ini-recommended and then edit it:

1. Open C:\php then copy the file php.ini-recommended to C:\WINDOWS

2. Rename it to be php.ini then open it with text editor

3. Set the doc_root to be: doc_root = c:\apache\apache2\htdocs

4. Set the extension_dir to: extension_dir = “C:\php\ext”

5. Uncomment (Remove the semicolon “;” from the beginning of the line) this line:

session.save_path = “c:/temp”

6. Uncomment the line: extension=php_oci8.dll

4.Edit the http.conf file:

1. Open the httpd file using any text editor, which exist on the path

C:\Apache\Apache2\conf

2. Find the line AllowOverride None and change the None value to be All

3. Look for the line DirectoryIndex index.html index.html.var and replace it with this line: DirectoryIndex index.html index.html.var index.php

4. Search for a section that has a lot of AddType commands, then added this line: AddType application/x-httpd-php .php so u have a total of 3 AddType command.

5. Search for a section has many Loads and add this line to it:

LoadModule php5_module modules/php5apache2.dll

5.Restart the Apache and the oracle database:

1. Restart the apache server using the cmd command (U can do it from the services but using the cmd has the advantage of showing errors while restarting the apache if there is any)

Open start -> run -> cmd -> cd c:\apache\apache2\bin (press enter)

The write apache –k restart (Press enter)

2. Restart the Oracle database

Open control panerl -> administrative tools -> services -> the restart all the services starting with Oracle

6. Test the connection:

1. To make the basic connection you need some information from the tnsnames.ora file, so follow the link C:\oracle\product\10.2.0\db_1\NETWORK\ADMIN Then open it

2. Open textpad page or use any text editor you want the past this code:

$db = “(DESCRIPTION=(ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.1.34)(PORT = 1521)))(CONNECT_DATA=(SID=orcl)))” ;

if ($c=OCILogon(“system”, “your database password“, $db)) {

echo “Successfully connected to Oracle.\n”;

OCILogoff($c);

} else {

$err = OCIError();

echo “Connection failed.” . $err[text];

}

Where the HOST is taken from your tnsnames.ora file and SID value is equal to your database name Then save the file with the name test.php

3. Open web browser page and type on the title: http://localhost/test.php

If it all worked well you will get white page with the result:

Successfully connected to Oracle.

NOTE: Recommended links to download the software’s:

Software	Version	URL
Oracle Database 10g Express Edition	10.2	http://www.oracle.com/technology/products/database/xe/
Apache HTTP Server	2.0.58	http://httpd.apache.org/download.cgi
PHP Hypertext Processor	5.1.3	http://www.php.net/downloads.php

Install Apache HTTP server:

me2blog — Sat, 18 Oct 2008 15:18:36 +0000

To install the Apache server, it’s straight forward …

Just follow the pictures

checking the information from HTML forms

me2blog — Wed, 01 Oct 2008 18:57:43 +0000

b4 u use the values in your script, u need to check the variables to make sure they contain what u expect ‘em to contain! Thus never trust info from user.

Checking for empty fields:

u can require the user to enter info in a field and check when the user didn’t and let him back to re-fill that field using:

empty($_POST['field_name']);

this function returns true if the field is empty,,, false otherwise !

Checking for specific format:

u can check using some built in functions like if u expect string, u can check using is_string and so on… for a table of these functions c this previous post Changing the order of statement execution

Using regular expressions to check user input:

u can aslo compare the info to a pattern to c if it matches if u care a lot about the information pattern using ereg function … for more in this ,,, check this previous post: pattern matching with regular expressions

Cleaning information:

strip_tags: this function removes all tags from the text, u can keep some tags:

$variable_name = strip_tags($_POST)['field_name'],” “);

htmlspecialchars: this function changes some special characters to HTML into HTML format that allow ‘em to display without any special meaning

Examples: < become &alt;

? become >

and & become &

$variable_name= htmlspecialchars($_POST)['field_name']);

trim: remove extra spaces at the beginning and the end of the field info, bcz it’s familiar that user enter spaces by mistake.

$variable_name= trim($_POST)['field_name']);

Example:

in this example, i will use the same forms in the previous post but i will check for three fields (first name, second name and last name) not to keep blank ,,, if so … the user will be asked to re-fill ‘em …. if they r not blank , then it will output the same information in that example….

Building the forms code:

Customer information

First name:
Second name:
Last name:
Street Address:
City:
Sex:	Male Female
Your Operating system:	Windows Linux Mac

the customer info code:

function set_sex(){
if ($_POST[Radio1]==”M”) {
$sex= “Male”;
}
else
{
$sex= “Female”;}
}

function print_info()
{

echo “Welcome “,$_POST['first_name'],”!
”;
echo “Your second name is: “,$_POST['second_name'];
echo “
Your last name is: “,$_POST['last_name'];
echo “
”;
echo “you are “, $sex;
echo ” living in: “, $_POST[city];
echo “ in the “, $_POST[st_address],” Street”;
echo “
and your operating systems are:
”;

if (isset($_POST['os0'])) {
echo “Windows
”;
}

if (isset($_POST['os1'])) {
echo “Linux
”;
}

if (isset($_POST['os2'])) {
echo “Mac
”;
}
return;
}

function blank_check(){
if (empty($_POST['first_name']))
{
echo “You didn’t enter your first name!
”;
$blank_check_var = TRUE;
}

if (empty($_POST['second_name']))
{
echo “You didn’t enter your second name!
”;
$blank_check_var = TRUE;
}

if (empty($_POST['last_name']))
{
echo “You didn’t enter your last name!
”;
$blank_check_var = TRUE;
}

return $blank_check_var;

}

//main
set_sex();
$check_var= blank_check();
if (!$check_var){
print_info();
}

The output after leaving the first name blank is:

You didn’t enter your first name!

The output after leaving the first and second name blank is:

You didn’t enter your first name!
You didn’t enter your second name!

The output after leaving the first, second and last name blank is:

You didn’t enter your first name!
You didn’t enter your second name!
You didn’t enter your last name!

Receiving the information from HTML forms

me2blog — Wed, 01 Oct 2008 13:42:55 +0000

The forms data r available at PHP built in array. As said earlier there two methods to send the data: POST and GET, so information from any form uses the method POST is available in the built-in array $_POST with the key for each field with it’s name! and information from any form uses the method GET is found in the array $_GET, and the key for each field is it’s name …

The information that user select from drop down menu or radio buttons r similarly available for use, but the situation is a lil different while using check boxes bcz the user can check more than one box, the information is in multidimentional array ,,,, but i think there is an easier wayL when u create check box bottons, name each buton a unique name, and get it from 1D array, it will be faster and easier to code … remember no one can c ur code ,,, every one will c the effect of ur code, so write it in the easiest way 4 u :p

What is the difference between POST and GET:

Get method: The form data is passed by adding it to the URL. The advantages for this method: it’s simple and fast but the disadvantages r less data to be passed and less secure (since the information r displayed in the browser).
Post method: The form data is passed as a package in a separate communication with the processing script. The advantages: unlimited information to be passed and more secure and the disadvantage is the overhead which slows the speed.

Example:

Customer information

First name:
Second name:
Last name:
Street Address:
City:
Sex:	Male Female
Your Operating system:	Windows Linux Mac

and now …. the customer_info.php code:

if ($_POST[Radio1]==”M”) {
$sex= “Male”;
}
else
{
$sex= “Female”;}

if (isset($_POST['os0'])) {
echo “Windows
”;
}

if (isset($_POST['os1'])) {
echo “Linux
”;
}

if (isset($_POST['os2'])) {
echo “Mac
”;
}

The output:

and after clicking the submit name button u will c the following page:

Welcome Noor!
Your second name is: A
Your last name is: Adiga
you are Female living in: Aqaba in the Abc ST Street
and your operating systems are:
Windows

working with HTML forms

me2blog — Mon, 29 Sep 2008 14:12:17 +0000

For a web page tp be active, it must collect information from the user. which is done using HTML forms.

Displaying HTML forms:

there is two ways to do that, u can write the HTML code directly or inside the echo statement, which gives the browser html sentences.

page to open after click submit.php” method= “POST” >

field name” value = “default value to display“>

Submit button name“>

action: u write here the name of the page u want the user to go into after clicking the submit button
method: there r two ways of methods: POST and GET … i will talk about ‘em later in this blog
now, we start creating the fields using
name: the name of the field, will not be displayed, just to work with while taking information from it
value: this value will be written inside the field box at the beginning
now, to make the submit button, by putting the type = “submit”
value: this will be the text written over the button

Adding selection list:

Adding Radio Buttons:

radio name” value = “the value to be stored while receiving the info “> “text to display “

Its important to use the same name for all radio options. otherwise it won’t work probably!

Adding check boxes:

check box name” value= “value to be stored” > “text to display“

Example:

Customer information

First name:
Second name:
Last name:
Street Address:
City:
Sex:	Male Female
Your Operating system:	Windows Linux Mac

The output:

handling functions errors

me2blog — Wed, 24 Sep 2008 12:23:34 +0000

Sometimes functions fail, sad but true. ur script should anticipate any possible function failer and handle the situation like displaying ur wn message error. this can be done using die statement

function_name () or die(“ur message“);

The die statement stops the script and prints out whatever u haved entered in its message. is is when the function returns false !

but remeber that u should shut off the display for error messages, otherwise ur used will c 2 error messages.

U can also handle possible functions faileres by using the function call as condition.

if (!function_name($variable))

{

echo “ur error message here“;

exit();

}

the exit statement does the same as die statement!

Passing values to a function

me2blog — Wed, 24 Sep 2008 12:08:29 +0000

you can pass values to a function by adding the values between parantheses when u call the function but before that u should define the values while defining the function

While passing values, make sure of the following:

1. passing the right data type:

the value passed can be any data type, including arrays and objects. A good practice is to check the value type before using it. especailly when u r taking these values from the user.

To use built-in functions that check the type, see this previous post:

Changing the order of statement execution

2. passing values in the correct order:

when u call the function test($a,$b); using test($x,$y);

then $a = $x and $b = $y …. each variable will take a value in order, if u call test($y,$x);

then $a = $y and $b = $x ,,, which is not the same … so pay attention to the order!

3. passing the correct number of values:

If u pass less numbers of values then the PHP will assign the missing values to be NULL and u will have a warning message.

if u pass many values than the function expected, it will ignore the extra values!

Note: u can assign default value for ur variables, so in the case that u forget to pass some values, the function will user their defaults

function function_name($varibale1= “default value”, $variable2= “default value”)

{

block of statements

return;

}

4. Passing values by reference:

when u pass values into variables in the function definition, u pass them by value (by default), u can make as many changes as u want inside the function, but when u back from the function , the value will return to it’s previous value b4 calling the function bcz u send a copy from the variable. If u want ur changes to affect the variable pass that variable by reference (think about it as u pass a pointer) any changes inside the function will stay after exiting the function!

Passing by reference is used mainly when passing really large values bcz it’s much faster!

Example:

function welcome_by_name ($name= “Visitor”)
{
echo “Welcome “, $name;
return;
}

echo “Passing the name \”Noor\” to the welcome function
“;
welcome_by_name(“Noor”);
echo “
Using the default value while calling the function
”;
welcome_by_name();

The output:

Passing the name “Noor” to the welcome function
WelcomeNoor
Using the default value while calling the function
Welcome Visitor

Creating reusable code(functions)

me2blog — Wed, 24 Sep 2008 11:26:10 +0000

A function is a group of PHP statements that perform a specific task, u can use the function whenever u need to perform the task.

Defining functions:

function function_name ()

{

block of statements

return;

}

The return statement stops the function and returns to the main script, it is not required but it makes the functions easier to understand.U can write a function anywhere in the script, but the usual is to put all functions together at the beginning of the script file.

Returning values back from functions:

U can pass value back from a function, using the return statement. it can only return one value. However remember that the return value can be an array; thus it is actually more than one value!

u can also use the return statement in a conditional statement to end the function.

Example:

function welcome()
{
echo “Welcome”;
return;
}
function name()
{
return Noor;
}
?>

Functions in PHP

$name_variable= name();
welcome();
echo “ $name_variable”;
?>
The output:

Functions in PHP

Welcome Noor

Using variables in functions (another method to return more than 1 value):

u can create as many variables as u wish inside the function, these variables r local. which means that they r accessable inside the function, also notice that the function can’t access any variable inside the function except in the case that this variable is set to be global!

by using global variables inside the function, u can return as many value as u wish

Example1 ( Local variables ,,, notice how u don’t get the result u want ):

$x=3;
$y=2;

function addition()
{
$sum= $x + $y;
}
addition();

echo “The sum result =”, $sum;
?>

The output for the first example:

The sum result =

Example2:

function addition($x1,$y1)
{
global $sum;
$sum= $x1 + $y1;
return;
}

$x=5;
$y= 2;

addition($x,$y);

echo “The sum result =”, $sum;
?>

The output for Example2:

The sum result =7

Repeating actions by using loops

me2blog — Sat, 20 Sep 2008 19:34:58 +0000

Loops r used frequently in scripts to set up a block of statements that repeated. The loop ca repeated according to:

Specific number of times
until a certain condition is met

there r three types of loops:

1. For loop:

In this type of loops, we set up a counter and repeats a block of statement until the counter reaches a specific number. u set at the beginning a counter value, set the ending value and set how u want the counter to be incremented or decremented.

for (starting_value ; ending condition ; increment)

{

block of statement

}

starting value: its the statement that sets up a variable to be ur counter and sets its initial value
ending condition: This is the statement that sets ur ending value, as long as the condition is true, the loop will keep executed
increment: The statement that increments ur counter

Notice that u can nest as much loops as u wish.

Example:

for ($i=1; $i<=5; $i++)
{
echo “This is line number “,$i,”
”;
}
?>

The output:

This is line number 1
This is line number 2
This is line number 3
This is line number 4
This is line number 5

2. advanced for loop:

for ( beginning statements ; conditional statements ; ending statements )

{

block of statement

}

beginning statements: they r executed once at the start of the loop, they can be any statements to set up any need values or other statements u want to execute before the loop starts
the conditional statements: they r tested for each iteration of ur loop
the ending statements: they executed once at the end of the loop

Each statements section can contain as many statements as u wish, just make sure to separate ‘em using commas, and to separate each section using semicolon ; and remember that any section can be empty

3. while loops:

A while loop continue repeating as long as certain conditions r true, first of all u set up a condition, the condition is tested at the top of each loop and it will repeats till the condition is false.

while( condition)

{

block of statements

}

Example:

in this example we have a variable called $array and it contain names, we will make a while loop to search for specific name if exist and if so to know how many times it exist.

in this example I used the if statement, if u r confused about it, u can check my previous post:

Using conditional statements

also I used arrays, if u ‘ve any problems with understand it, plz check: Creating arrays

The code for the example:

$array = array (“Ali”,”Tony”,”Moneer”,”Sameer”,”David”, “Sami”, “George”,”Joe”,”Alicia”,
“Sarah”, “sally”,”Moneka”, “Richeal”,”Phebi”,”Razan”,”Mellanie”,”Noor”,”Sabrina”,”Ali”,”Tony”,”Tony”);

$array_size= sizeof($array);
$counter=0;
$searchvalue=”Tony”;
$search_repeated=0;

while ($counter<=$array_size)
{
If ($array[$counter] == $search_value)
{
$search_repeated ++;
}
$counter ++;
}

if ($search_repeated ==0)
{
echo “The item “,$search_value, ” was not founded in the array”;
}
else
{
echo “The item “,$search_value, ” was founded “, $search_repeated , ” in the array”;
}
?>

The output:

The item Tony was founded 3 in the array

4. do while loops:

They r so similar to the while loops, except that the conditions r tested at the bottom of each loop. Therefor the loop will execute at least once if the conditions r false.

{

block of statements

} while (conditions);

Note1: Avoiding infinite loops:

U can reach a point where the loop will never ends, in this case u have a serious problem in ur loop, so make sure of the condition and that ur counter(for loops) is incremented. If u r using PHP for a web page it will stop by itself after 30 seconds (it will timed out).

Note2: Breaking out of loops:

there r two types to break out of the loop

break: breaks completely from the loop and continue to the next statement after the loop
continue: skips to the end of the loop where the condition is tested, id the condition is positive then the scripts continue from the beginning of the loop.

Using conditional statements

me2blog — Sat, 20 Sep 2008 14:30:39 +0000

Conditional statements executes a block of statements only when certain conditions r true.

1. Using If statement:

The general format of and if conditional statement is as follows:

if (condition)

{

block of statements

}

elseif (condition)

{

block of statements

}

else

{

block of statements

}

Explanations:

if: The block of statements executes if the condition is true only and after executing it, the script moves to the next instruction skipping any elseif or else statements (only 1 part will execute). If the condition is false then it will move to line below the curly braes, whatever it’s elseif or else or another statement.
elseif: This section is optional, u can use more than one elseif, they executes in the same way as the above if
else: This section is also optional, only one else statement is allowed and this part doesn’t test any condition bcz PHP consider that when the script reach that point then no other statments above was executed and thus the else condition will be true.

Example:

we want to print the student grade with a message and with a grade symbol, like the following:

grade range	Message	grade symbol
99-89	Excellent	A
90-79	Very good	B
80-69	Good	C
70-59	O.K	D
60-49	Poor	E
less than 50	Failed!	F

$grade_check= 75;

if ($grade_check<100 and $grade_check >89)
{
$grade= “A”;
$message = “Excellent”;
}
elseif ($grade_check <90 and $grade_check > 79)
{
$grade= “B”;
$message = “Very good”;
}
elseif ($grade_check <80 and $grade_check > 69)
{
$grade= “C”;
$message = “Good”;
}
elseif ($grade_check <70 and $grade_check >59)
{
$grade= “D”;
$message = “O.K”;
}
elseif ($grade_check <60 and $grade_check> 49)
{
$grade= “E”;
$message = “Poor”;
}
else
{
$grade= “F”;
$message = “Failed!”;

}

echo “for the student grade = “, $grade_check, “
”,$message, “ ( “,$grade, ” )
”;
?>

The output for three random grades:

for the student grade = 75
Good ( C )

for the student grade = 64
O.K ( D )

for the student grade = 95
Excellent ( A )

Note1: U can test 4 negative if statements that is the block of statements r executed when the condition is false, by adding exclamation point (!) at the beginning of the condition. i.e. if( ! $number >5) then the block of statements will execute only if the $number contains value less than or equal 5.

Note2: U can have nested if statement by adding if statement inside another if, and so on. this is called nesting. but remember that u can’t reach the inner if , if the outer if isn’t true … the block of statements will execute only if all the if’s r true in the path till reach that block!

1. Using Switch statement:

switch statement is a good option when u ‘ve a lot of conditions. The switch statement tests the value of one variable and then executes the block of variables that matching the value in the variable.

switch ($variable_name)

{

case value:

{

Block of statements

}

case value:

{

Block of statements

}

default:

{

Block of statements

}

The default section is optional, works like else in the if statements, and it will exucute only it the variable value didn’t match any case statement, u can place it anywhere but it make more sense to add it at the end of the switch statement.
The break statements r essentials, if u didn’t write it, if the case if true it will contiue to execute all the cases below it without checking the condition.

Example:

the same as the above example but we will write it using switch
$grade_check_s= 48;
switch ($grade_check_s)
{case ($grade_check_s <100 and $grade_check_s >89):
{
$grade_s= “A”;
$message_s = “Excellent”;
break;
}
case ($grade_check_s <90 and $grade_check_s >79):
{
$grade_s= “B”;
$message_s = “Very good”;
break;
}
case ($grade_check_s <80 and $grade_check_s >69):
{
$grade_s= “C”;
$message_s = “Good”;
break;
}
case ($grade_check_s <70 and $grade_check_s >59):
{
$grade_s= “D”;
$message_s = “O.K”;
break;
}
case ($grade_check_s <60 and $grade_check_s >49):
{
$grade_s= “E”;
$message_s = “Poor”;
break;
}

default:
{
$grade_s= “F”;
$message_s = “Failed!”;

}
}

echo “for the student grade = “, $grade_check_s, “
”,$message_s, “ ( “,$grade_s, ” )
”;
?>

The output for three random grades:

for the student grade = 48
Failed! ( F )

for the student grade = 86
Very good ( B )

for the student grade = 77
Good ( C )

pattern matching with regular expressions

me2blog — Fri, 19 Sep 2008 14:47:30 +0000

Sometimes u need to compare character strings to c whether they fit certain characteristics rather than to check if they match exact values. For this type of comparison, u compare the string to a pattern, they r called regular expressions. One common use of ‘em is to check the input from a web page form.

In the table below some special characters: (all other characters r literal without any special meaning):

character	Meaning	Example	Matched	Unmatched
^	Beginning	^n	noor	my name is noor
$	end of line	n$	lookin$	looking
.	any single character	…	ice	A
?	the preceding character is optional	Noo?r	Nor, Noor	Nour
()	group literal characters into a string that must be matched exactly	N(oo)r	Noor	Nour
[]	enclose a set of optional literal characters	No[ou]r	Noor,Nour	Nor
[^]	enclose a set of non-matching optional characters	Noo[^v]r	Noor	Noovr
-	a range of possible	No[n-p]r	Noor, Nonr	Noar
+	one or more of the preceding character	Noo+r	Noooor,Nooor	Noor
*	zero or more of the preceding character	Nooo*r	Noor, Nooor	Norr
{n}	repeat n times	No{2}r	Noor	Nooor
{n1,n2}	specifies a range of changes	N{1-4}r	Noor	Noooooooooor
\	The following character is literal (not special character)	N\*r	N*r	Noor
(\|\|)	a set of alternate string	(Noor \|\| Nour)	Noor, Nour	Sarah

comparing string to patterns:

u can compare string to patterns using ereg:

ereg (“pattern“,value);

It will return TRUE or FALSE

Joining multiple comparisons:

U can connect as many conditions as u want in one condition statement, using one of this three words:

and: both comparisons r true
or: one of the comparisons is true or both r true
xor: one of the comparisons is true but not both r true

The compression using and r tested first, then xor and at the end or r compared. If u want to change the order they r checked, simply use parentheses, its better to use parentheses even if u know the order, bcz unnecessary parentheses can’t hurt but to have unexpected result can!

Note: In some programming languages like C++ and Jave, u find || and && for (or and and in order), they work in PHP as well, they will do the same or and and functionality but || is checked before or , also && is checked before and!

Changing the order of statement execution

me2blog — Fri, 19 Sep 2008 13:57:02 +0000

PHP scripts r series of instructions in a file and they r executed one after another from the beginning (top of the file) to the end.

To change the flow of the script u need to add complex statements, PHP provides two types of ‘em:

Conditional statements: U set up statements that execute only if a certain conditions r met. (If statement and switch statement)
Looping statements: U can execute a statements repeatedly; this is called looping. (for, while and do… while statements)

Both types of complex statements execute a block of statements based on a condition. That is if the condition is true in the “Conditional statements” then the statements will execute once but if the condition is true in the “Looping statements” then the statements will execute till the condition become not true.

Conditions and conditions operators:

Conditions r expressions that PHP tests or evaluates to c whether they are TRUE or FALSE, to set up conditions u compare values.

U can use several conditions operators, and they r listed in the table below:

Operator	It’s use
==	to compare two values
===	to compare two values in both values and data type
>	To compare if the first value(to the left) is larger than the second value (to the right)
>=	To compare if the first value(to the left) is equal or larger than the second value (to the right)
<	To compare if the first value(to the left) is less than the second value (to the right)
<=	To compare if the first value(to the left) is equal or less than the second value (to the right_
!= or <>	returns true if the two values r not equal
!==	returns true if the two values r not equal in their value or in their data type

note1: U can compare both numbers and strings, strings r compared according to their ASCII value.

note2: Pay attention when u want to compare values to use double equal == not single equal, coz the single equal will assign the value and it will always return TRUE. i.e: $a==3; (compression) but $a=3; (a will be equal 3 after executing this statement).

Checking variable content:

there is some special test provided by PHP for variables, such as:

Test	Explanation	variable data type
isset($variable_name);	TRUE if the variable is set even if nothing is stored in it	variable
empty($variable_name);	TRUE if:1. variable is not set 2.value =0 3. no character for string values	variable
is_int($variable_name);	TRUE if the data type for the variable is integer	number
is_array($variable_name);	TRUE if the variable is array	variable
is_float($variable_name);	TRUE if the data type for the variable is floating point	number
is_null($variable_name);	TRUE if the value =0 in the variable	variable
is_numeric($variable_name);	TRUE if the string inside the variable is numeric string	string
is_string($variable_name);	TRUE if the variable is string	string

u can also test for the negative for any of the above tests by adding ! before it.

i.e.. if u want the reuslt to be FALSE when the variable is set use !isset($variable_name);

Multidimensional arrays

me2blog — Thu, 18 Sep 2008 03:24:11 +0000

The main Idea in multidimensional array that u store value with more than 1 key. So it looks like an array of arrays.

If u want to store this table in PHP:

Age/Location	U.K	Jordan	Germany
22	Tony	Noor	Victoria
25	Isabella	Mohammad	Sabrina
27	Linda	Hadeel	Brian

each cell ‘ve two keys rather than one, so this will be a 2-D array

Keys : 22 & U.K = Tony
Keys: 22 & Jordan = Noor
keys : 22 & Germany = Victoria
and so on ….

Creating multidimensional arrays:

u can create multidimensional arrays the same way u create one-multidimensional array!

U can create ‘em with a series of direct statements $array_name[key1][key2]= “Value“;
U can use shortcut to allow PHP to chose the keys $array_name[key1][]= “value“;
U can use array statement $array_name = array ( “key1” => array (“key2“=> “values“), “key1” => array (“key2“=> “values“), …. );

viewing multidimensional arrays:

u can view multidimensional arrays in the same way u can view one-dimensional array, using var_dump or print_r statements!

Using multidimensional arrays in statements:

u can follow the same procedure u use with one-dimensional arrays to work with this kind of arrays (using ‘em with variables or simply edit ‘em) and u can echo ‘em … but u should pay attention if u try to combine the values with double quotes that u need to use curly braces to enclose the variable name.

echo ” words here {$array_name[key1][key2]} “;

Note: statements that convert string to arrays (and vice versa) and convert variable to arrays (and vice versa) and statement for arrays operations MOST of ‘em won’t make sense with multidimensional arrays and won’t work correctly

Walking through a multidimensional arrays:

u can walk through two-dimensional arrays using two foreach statement, one foreach statement inside the other (nesting).

If u want to read more about foreach, check my previous post walking through an array

Example:

$age_loc[22][uk]=”Tony”;
$age_loc[22][jordan]=”Noor”;
$age_loc[22][germany]=”Victoria”;

$age_loc[25][uk]=”Isabella”;
$age_loc[25][jordan]=”Mohammad”;
$age_loc[25][germany]=”Sabrina”;

$age_loc[27][uk]=”Linda”;
$age_loc[27][jordan]=”Hadeel”;
$age_loc[27][germany]=”Brian”;

echo “View \$age_loc array using print_r

”;

print_r($age_loc);

echo “

”;

echo “View the value with the keys 27 and germany: {$age_loc[27][germany]}
”;

echo “
Now, lets walk through the array and echo each element
”;

foreach ($age_loc as $age_key => $age)
{
foreach ($age as $location => $value)
{
echo “The person whom his/her age = $age_key & from $location is $value
”;
}
}

and the output:

View $age_loc array using print_r

Array
(
    [22] => Array
        (
            [uk] => Tony
            [jordan] => Noor
            [germany] => Victoria
        )

    [25] => Array
        (
            [uk] => Isabella
            [jordan] => Mohammad
            [germany] => Sabrina
        )

    [27] => Array
        (
            [uk] => Linda
            [jordan] => Hadeel
            [germany] => Brian
        )

)

View the value with the keys 27 and germany: Brian

Now, lets walk through the array and echo each element
The person whom his/her age = 22 & from uk is Tony
The person whom his/her age = 22 & from jordan is Noor
The person whom his/her age = 22 & from germany is Victoria
The person whom his/her age = 25 & from uk is Isabella
The person whom his/her age = 25 & from jordan is Mohammad
The person whom his/her age = 25 & from germany is Sabrina
The person whom his/her age = 27 & from uk is Linda
The person whom his/her age = 27 & from jordan is Hadeel
The person whom his/her age = 27 & from germany is Brian

Some arrays operations

me2blog — Wed, 17 Sep 2008 19:42:18 +0000

Summing arrays:

To add all the elements in the array, use this statement:

$sum_result= array_sum($array_name);

If u try to add some elements which is not numbers, PHP will autiomatically convert them to number with the zero value!

Example:

$sum_array= array (1,2,3,4);
$sum_result = array_sum($sum_array);

echo “The sum of all elements in the \$sum_array = “,$sum_result;
?>

The output:

The sum of all elements in the $sum_array = 10

Removing duplicate items:

to remove duplicate items, use the following statement:

$array_without_duplicate_values= array_unique($array_name);

Example:

$aaray_with_duplicate= array (“A1″,”B1″,”C1″,”A1″);
$aaray_without_duplicate= array_unique($aaray_with_duplicate);

echo “The array with duplicate elements

”;

print_r($aaray_with_duplicate);

echo “

”;
echo “The array without duplicate elements

”;

print_r($aaray_without_duplicate);

echo “

”;
?>

The output:

The array with duplicate elements

Array
(
    [0] => A1
    [1] => B1
    [2] => C1
    [3] => A1
)

The array without duplicate elements

Array
(
    [0] => A1
    [1] => B1
    [2] => C1
)

Exchanging keys and values:

To exchange values and keys in an arrays:

$array_exchanged= array_flip($array_name);

Example:

$array_to_flip = array (“A1″,”B1″,”C1″);
$array_exchanged= array_flip($array_to_flip);
echo “The array before fliping its value with its keys

”;

print_r($array_to_flip);

echo “

”;
echo “The array after fliping its value with its keys

”;

print_r($array_exchanged);

echo “

”;
?>

The output:

The array before fliping its value with its keys

Array
(
    [0] => A1
    [1] => B1
    [2] => C1
)

The array after fliping its value with its keys

Array
(
    [A1] => 0
    [B1] => 1
    [C1] => 2
)

Finding array size:

u can use count or sizeof statement to find the size of an array

$size_value= count($array_name);

$size_value= sizeof($array_name);

the number of elements will be stored in $size_value for each statement!

Example:

$array_to_find_size= array (“A1″,”B1″,”C1″,”A2″,”B2″,”C2″);
$size_count = count($array_to_find_size);
$size_sizeof= sizeof($array_to_find_size);

echo “Size of \$ array_to_find_size using count : “, $size_count,
“
Size of \$ array_to_find_size using sizeof : “, $size_sizeof;
?>
The output:

Size of $ array_to_find_size using count : 6
Size of $ array_to_find_size using sizeof : 6

comparing arrays

me2blog — Wed, 17 Sep 2008 18:50:58 +0000

can identify the elements that r the same or the elements that r different.

To find different elements:

$difference_array= array_diff($array1, $array2, ….);

$difference_array contains the elements in array1 and not in array2 or the other arrays.

The order in which u list the arrays make a diffrenence.

To find arrays elements that differ in either value or key, use this statement:

$difference_array= array_diff_assoc($array1, $array2, ….);

To find same elements:

U can find the same elements in two arrays or more using:

$similar_array= array_intersect($array1, $array2, ….);

If u want both the value and the key to be the same, use:

$similar_array= array_intersect_assoc($array1, $array2, ….);

Example:

$array1_diff= array (“A1″,”B1″,”C1″,”A2″,”B2″,”C2″);
$array2_diff= array (“A1″,”B1″,”C1″);
$array3_diff= array (“A1″,”B1″,”C1″,”B2″,”C2″);

$diff= array_diff($array1_diff,$array2_diff,$array3_diff);

echo “The difference:

”;

print_r($diff);

echo “

”;

$same= array_intersect($array1_diff,$array2_diff,$array3_diff);
echo “
The same elements:

”;

print_r($same);

echo “

”;

The output:

The difference:

Array
(
    [3] => A2
)

The same elements:

Array
(
    [0] => A1
    [1] => B1
    [2] => C1
)