Pre-increment

Pre-increment is the ++ operator, used on a variable, when it is placed before the variable. This means that the increment happens before the variable is read: in this case, the first echo displays 2, as the increment happens before the echo call.

There is also a pre-decrement, which uses the operator --, and reduces the variable of 1.

Pre-increment and pre-decrement have a corresponding post-increment and post-decrement.

<?php

    $a = 1;
    echo ++$a; // displays 2
    echo $a;   // displays 2

?>

Documentation

See Also

• Understanding the Increment and decrement operators in PHP
• Useless post increment/decrementPHP-W1090

Related

• Post-increment
• Addition
• Variables
• Increment
• Double
• Minus -
• Operators