How to use For-Each Loop in PHP?

[Bigga Lexx]

Hello friends,
I have just started the PHP programming language, so you can consider me as a rookie. I have done with some loop in PHP but I get confused when the for-each loop comes.!! I thought that you guys can explain me in better way. So please tell me how to use For-Each Loop in PHP? Hope that you would help me as soon as possible.!!

[MindSpace]

The loops are the most complex loops in PHP. They work like loops of the C language syntax for loops is as follows :

PHP Code:

for (expr1; expr2; expr3)
    statement 


The first expression (expr1) is evaluated (executed), what happens at the beginning of the loop. At the beginning of each iteration, expr2 is evaluated. If it evaluates to TRUE, the loop continues and the statement is executed. If it evaluates to FALSE, the execution of the loop ends. At the end of each iteration, expr3 is evaluated (executed).

[Modifier]

I would like you to tell about the For Loop, since it is an important and complex loop. Expressions can be empty or may contain multiple expressions separated by commas. Expr2 In all expressions separated by a comma are evaluated but the result is obtained since the last part. If expr2 is left blank, meaning it is an infinite loop. PHP implicitly considers it as TRUE, like C. This is not really very useful, unless you want to end the loop by the conditional break.

[Reegan]

PHP 4 introduced a foreach construct, much like Perl or other languages. It is a simple way to browse a table. Foreach works only on arrays, and return an error if you try to use a variable of another type or uninitialized. The following are two syntaxes of for-each loop :

PHP Code:

foreach (array_expression as $value)
    statement
foreach (array_expression as $key => $value)
    statement 


The first form loops over the array array_expression. At each iteration, the value of the current element is assigned to $ value and the internal array pointer is advanced by one. The second form is exactly the same thing, but the key to the current element is assigned to the variable $ key.

[Zecho]

There are some things that you should know before using the for-each loop into the coding. When foreach first starts, the internal array pointer is automatically reset to the first array element. This means you will not have to call reset () before a foreach loop. Unless the array is a reference, foreach operates on a copy of the specified array and not the array itself. Foreach affects the internal array pointer. Do not use without resetting before.

[CodGuru]

Since PHP 5, you can easily modify elements of an array by preceding $ value of &. This will assign a reference instead of copying the value. The following example may help you in understanding the topic :

PHP Code:

<?php
$arr = array(1, 2, 3, 4, 5);
foreach ($arr as &$value) {
    $value = $value * 2;
}

unset($value);
?>

Reference of a $value and the last array element remain even after the foreach loop. It is recommended to destroy it by unset().