PHP While Loop

PHP While Loop

PHP while loop can be used to traverse set of code like for loop. It should be used if number of iteration is not known.

Syntax :

while(condition)
{  
      //code to be executed  
} 

Alternative Syntax :

while(condition):  
//code to be executed  
    
endwhile;

Image Source : ZenTut


Example

<?php  
$n=1;  
while($n<=10)
{  
      echo "$n<br/>";  
      $n++;  
}  
?>  
Output :
1
2
3
4
5
6
7
8
9
10

Alternative Example

<?php  
$n=1;  
while($n<=10):  
echo "$n<br/>";  
$n++;  
endwhile;  
?>  
Output :
1
2
3
4
5
6
7
8
9
10

PHP Nested While Loop

We can use while loop inside another while loop in PHP, it is known as nested while loop.

In case of inner or nested while loop, nested while loop is executed fully for one outer while loop. If outer while loop is to be executed for 3 times and nested while loop for 3 times, nested while loop will be executed 9 times (3 times for 1st outer loop, 3 times for 2nd outer loop and 3 times for 3rd outer loop).

Example

<?php  
$i=1;  
while($i<=3)
{  
      $j=1;  
      while($j<=3)
      {  
            echo "$i   $j<br/>";  
            $j++;  
      }  
$i++;  
}  
    ?>  
Output :
1 1
1 2
1 3
2 1
2 2
2 3
3 1
3 2
3 3