The While loop function in Perl is used to execute statements till the condition becomes false.

  While (expr1)
    {
      Statement to be executed
    }

In the above syntax the code segment is executed till the "expr1" becomes false, here the iteration never stops even the condition becomes false until it checks the "expr1".

    #! C:\programfiles\perl\bin\perl
    print "content-type: text/html\n\n";
    $c=0;
    while($c<=5)
     {
      print "This is line".$c."<br>";
      $c++;
     }

    This is line0
    This is line1
    This is line2
    This is line3
    This is line4
    This is line5

In the above example when the value of $c becomes 6, the iteration continues till the "expr1" is checked and as the condition is false the code execution is stopped.