PHP Increment/Decrement Operator, Pre/Post Incrementing, Pre/Post Decrementing Operators

Topic

What are the Incrementing/Decrementing Operators ?

Explanation

PHP supports pre/post increment and decrement operators. The following table lists all the operators

Example	Name	Effect
++$a	Pre-increment	Increments $a by one, then returns $a.
$a++	Post-increment	Returns $a, then increments $a by one.
--$a	Pre-decrement	Decrements $a by one, then returns $a.
$a--	Post-decrement	Returns $a, then decrements $a by one.

Post Increment/Decrement Operators
Example:

    <?php
    $a = 5;
    //Post Increment
    echo "Value of a: " . $a++ ."<br />\n";
    echo "Value of a post incremented: " . $a . "<br />\n";
    //Post Decrement
    $a = 5;
    echo "Value of a: " . $a-- . "<br />\n";
    echo "Value of a post decremented: " . $a . "<br />\n";
    ?>

Result:

    Value of a: 5
    Value of a post incremented: 6
    Value of a: 5
    Value of a post decremented: 4

In the above example, when the post increment or decrement operator is called it returns the same value, after that it increments or decrements the value.

Pre Increment/Decrement Operators
Example:

    <?php
    Pre Increment
    $a = 5;
    echo "Pre incremented value: " .++$a . "<br />\n";
    echo "Value is same: " .$a . "<br />\n";
    Pre Decrement
    $a = 5;
    echo "Pre decremented value: ".--$a ."<br />\n";
    echo "Value is same: ".$a ."<br />\n";
    ?>

Result:

    Pre incremented value: 6
    Value is same: 6
    Pre decremented value: 4
    Value is same: 4

In the above example, when the pre increment or decrement operator is called it returns decremented or incremented value first.

Incrementing/Decrementing Operators in PHP