Increment

Increment refers to the process of increasing or adding a small amount to a value, or simply one unit.

Increments usually refers to the pre-plusplus and post-plusplus. Increment applies to numbers, both decimal and integers. It also applies to strings, though the feature has been moved to functions. Increment works on booleans: it always produces 1 first, then, since it was turned into an integer, it goes on with numbers.

<?php

    $a = 1;

    echo ++$a; // pre plus plus : displays 1, and $a ends with 2

    echo $a++; // post plus plus

    echo $a += 1; // increment

?>

Documentation

Related : Pre-increment, Post-increment, String Increment