The While statement executes a block of code if and as long as a specified condition evaluates to true. If the condition becomes false, the statements within the loop stop executing and control passes to the statement following the loop. The While loop syntax is as follows:
while (condition)
{
  code to be executed;
}

The block of code associated with the While statement is always enclosed within the { opening and } closing brace symbols to tell PHP clearly which lines of code should be looped through.

While loops are most often used to increment a list where there is no known limit to the number of iterations of the loop.

Let's have a look at the examples. The first example defines a loop that starts with i=0. The loop will continue to run as long as the variable i is less than, or equal to 10. i will increase by 1 each time the loop runs:
$i=0;
while ($i <= 10) { // Output values from 0 to 10
   echo "The number is ".$i."
";
   $i++;
}
?>