Pre/Post-Increment & Pre/Post-Decrement

This may seem a bit absurd, but there is even a shorter shorthand for the common task of adding 1 or subtracting 1 from a variable. To add one to a variable or "increment" use the "++" operator:

To subtract 1 from a variable, or "decrement" use the "--" operator:

In addition to this "shorterhand" technique, you can specify whether you want to increment before the line of code is being executed or after the line has executed. Our PHP code below will display the difference.

PHP Code:

$x = 4; 
echo "The value of x with post-plusplus = " . $x++; 
echo "<br /> The value of x after the post-plusplus is " . $x; 
$x = 4; 
echo "<br />The value of x with with pre-plusplus = " . ++$x; 
echo "<br /> The value of x after the pre-plusplus is " . $x;

Display:

The value of x with post-plusplus = 4
The value of x after the post-plusplus is = 5
The value of x with with pre-plusplus = 5
The value of x after the pre-plusplus is = 5

As you can see the value of $x++ is not reflected in the echoed text because the variable is not incremented until after the line of code is executed. However, with the pre-increment "++$x" the variable does reflect the addition straight away .

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