For Loop

For loop sets condition variable initialization and modification on one line.

Syntax

for(initialization; condition; modification) { // Loop's body. }

initialization - sets variables used in the loop (like $i = 0)

condition - Until when the cycle will keep on executing. Like $i <= 10.

modification - could avoid infinite loops (like $i++).

Basic Example

Let's have a program that prints each number from 1 to 10.

<?php for ($i = 1; $i <= 10; $i++) { echo $i . " "; }

Output:

1 2 3 4 5 6 7 8 9 10

The initialization$i = 1 performs first - before loop's iterations.

$i++ executes in the end of every iteration.

Infinite loops

An infinite for-loop has a condition that's always true or it's unset.

Let's look at the following example

<?php for (;;) { echo "0 "; }

Output:

0 0 0 0 0 0 0 0 0 ...

Since condition is not specified the loop repeats infinitely.

There is more than 1 way of defining infinite loop.

<?php for ($i = 1;;$i++) { echo $i . " "; }

Output:

1 2 3 4 5 6 7 8 9 10 11 ...

In this case the only segment that's not specified is the condition therefore the cycle doesn't end.