(PHP 4, PHP 5)
I cicli while sono i più semplici tipi di loop in PHP. Questi cicli si comportano esattamente come nel C. La forma base di un'istruzione while è:
while (expr)
statement
The meaning of a while statement is simple. It
tells PHP to execute the nested statement(s) repeatedly, as long
as the while expression evaluates to
TRUE. The value of the expression is checked
each time at the beginning of the loop, so even if this value
changes during the execution of the nested statement(s), execution
will not stop until the end of the iteration (each time PHP runs
the statements in the loop is one iteration). Sometimes, if the
while expression evaluates to
FALSE from the very beginning, the nested
statement(s) won't even be run once.
Like with the if statement, you can group multiple statements within the same while loop by surrounding a group of statements with curly braces, or by using the alternate syntax:
while (expr):
statement
...
endwhile;
Gli esempi seguenti sono identici, ed entrambi stampano i numeri da 1 a 10:
<?php
/* example 1 */
$i = 1;
while ($i <= 10) {
echo $i++; /* the printed value would be
$i before the increment
(post-increment) */
}
/* example 2 */
$i = 1;
while ($i <= 10):
echo $i;
$i++;
endwhile;
?>