Loops in PHP ( for , while , do while , foreach)

Loops 

     

        A loop is a piece of code in a script automatically repeats . One complete execution of all statement within a loop is called an " iteration " or "pass" .

The length of a loop is a controlled by a conditional test made within the loop 

In PHP there are these four type of loop structure 

 

1 . for loop - performs a specified number of iteration .

2 . while loop - performs iteration only while a test made at the start of each                          iteration evaluates as TRUE

3 . do while loop - performs iterations only while a test made at the end of each                     iteration evaluates as TRUE 

4 . foreach loop - performs iteration through each element of an array 

Syntax 

     for ( initializer ; test-expression ; increment )

          {

              statement-to-be-executed

           }

PHP Programs

<?php

for($i=1; $i<4;$i++)

  {

     echo " outer loop iteration $i";

    for($j=1; $j<4; $j++)

    {

        echo "Inner loop iteration $j";

    }

  }

   

?>

Output

While Loop 

      while loop is an alternative to the for loop  

Syntax

      initializer

      while (test-expression)

          {

              statement-to-be-executed ; incrementer

           }

PHP Programs

<?php

    $number = array(10,20,30);

         // While Loop 

    echo "While Loop";

    $i=0;

    while($i<3)

     {

         echo " <dd>Element $i = $number[$i]";

         $i++;

     }

        // Do While Loop 

     echo " Do While Loop ";

     $i=0;

     do

      {

          echo " <dd>Element $i = $number[$i]";

          $i++ ;

      }

      while($i<3)

?>

    

Output

   

for loop 

   for loop performs three iteration 

 PHP Programs 

<?php

    for ($i=1 ; $i<4 ; $i++)

      {

          for($j=1 ; $j<4 ; $j++)

            {

                if($i==2 && $j==1)

                  {

                      echo " Running i =$i and j=$j";

                  }

            }

      }

?>

Output