An Introduction to PHP Loops - Explained with Examples

Guide
1

Loops are blocks of code that execute a specified number of times. Using loops reduces the number of lines of code.

PHP works with 4 different types of loops:

  • While loop
  • Do…while loop
  • For loop
  • Foreach loop

While loop

The while loop continues to excecute as long as the specified condition is true.

<?php  
    while(condition is true)  
    {  
        execute code;  
    }  
?>

Example:

<?php  
    $x = 1;
    while($x <= 3) 
    { 
        echo "x=$x ";
        $x++;
    } 
?>

Output:

    x=1 x=2 x=3

Do…while loop

In the do...while loop the block of code is executed before the condition is checked.

<?php
    do {
        execute code;
    } while (condition);
?>

Example:

<?php
    $x= 1;
    do {
        echo "x=$x ";
        $x++;
    } while ($x < 5);
?>

Output:

    x=1 x=2 x=3 x=4

For loop

The for loop is used when the number of times the block is to be executed is known in advance.

<?php
    for (variable initialisation; test condition; increment)
    { 
        execute code; 
    }
?>

Example:

<?php
    for ($x=1 ; $x <= 4 ; $x++)
    {
        echo "x= $x "; 
    }
?>

Output:

    x=1 x=2 x=3 x=4

Foreach loop

The foreach loop helps in traversing through arrays.

<?php
    foreach ($array as $value)
    { 
        executable code; 
    }
?>

Example

<?php
    $numbers= array("One", "Two", "Three"); 
    foreach ($numbers as $value)
    {
        echo "$value ";
    }
 ?>

Output:

     One Two Three
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