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PHP: Incrementing Decrementing Operators

Description

PHP supports C-style pre and post increment and decrement operators. The Increment/decrement operators operate only on variables and not on any value.

List of increment/decrement operators

Example Name Effect
++$x Pre-increment Increments $x by 1, then returns $x.
$x++ Post-increment Returns $x, then increments $x by 1.
--$x Pre-decrement Decrements $x by 1, then returns $x.
$x-- Post-decrement Returns $x, then decrements $x by 1.

Example:

<?php
$a = 10;
echo 'Value of $a is :'.$a;
echo '<br />After Pre-increment value of $a ( i.e. ++$a ) is: '.++$a;
$a = 20;
echo '<br />Value of $a is :'.$a;
echo '<br />After Post-increment value of $a ( i.e. $a++ ) is: '.$a++;
$a = 30;
echo '<br />Value of $a is :'.$a;
echo '<br />After Pre-decrement value of $a ( i.e. --$a ) is: '.--$a;
$a = 40;
echo '<br />Value of $a is :'.$a;
echo '<br />After Post-decrement value of $a ( i.e. $a-- ) is: '.$a--;
?>

Output:

Value of $a is :10
After Pre-increment value of $a ( i.e. ++$a ) is: 11
Value of $a is :20
After Post-increment value of $a ( i.e. $a++ ) is: 20
Value of $a is :30
After Pre-decrement value of $a ( i.e. --$a ) is: 29
Value of $a is :40
After Post-decrement value of $a ( i.e. $a-- ) is: 40

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PHP: Tips of the Day

PHP: How to fix error with xml2-config not found when installing PHP from sources?

All you need to do instal install package libxml2-dev for example:

sudo apt-get install libxml2-dev

On CentOS/RHEL:

sudo yum install libxml2-devel

Ref : https://bit.ly/34hOrfG