PHP Looping - For Loops

 

Loops execute a block of code a specified number of times, or while a specified condition is true.


The for Loop
The for loop is used when you know in advance how many times the script should run.

Syntax
for (init; condition; increment)
{
code to be executed;
}

Parameters:

init: Mostly used to set a counter (but can be any code to be executed once at the beginning of the loop)
condition: Evaluated for each loop iteration. If it evaluates to TRUE, the loop continues. If it evaluates to FALSE, the loop ends.
increment: Mostly used to increment a counter (but can be any code to be executed at the end of the loop)
Note: Each of the parameters above can be empty, or have multiple expressions (separated by commas).

Example
The example below defines a loop that starts with i=1. The loop will continue to run as long as i is less than, or equal to 5. i will increase by 1 each time the loop runs:

<html>
<body>

<?php
for ($i=1; $i<=5; $i++)
{
echo "The number is " . $i . "<br />";
}
?>

</body>
</html>


Output:

The number is 1
The number is 2
The number is 3
The number is 4
The number is 5




The foreach Loop
The foreach loop is used to loop through arrays.

Syntax
foreach ($array as $value)
{
code to be executed;
}

For every loop iteration, the value of the current array element is assigned to $value (and the array pointer is moved by one) - so on the next loop iteration, you'll be looking at the next array value.

Example
The following example demonstrates a loop that will print the values of the given array:

<html>
<body>

<?php
$x=array("one","two","three");
foreach ($x as $value)
{
echo $value . "<br />";
}
?>

</body>
</html>


Output:

one
two
three