Pre and post increment / decrement — how do they work?

PHP supports the increment and decrement system known from the C language. See how they work.

PHP supports incrementation and decrementation

The increment and decrement operators work only on strings and numbers. On objects, tables, booleans and resources they do nothing. Regarding null, decrementation does not matter, but incrementation returns 1.

++$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.

Number pre-increment example

$i = 1;
echo (++$i + 1); // 3
echo $i; // 2

Number post-increment example

$i = 1;
echo ($i++ + 1); // 2
echo $i; // 2

Number pre-decrement example

$i = 1;
echo ( —- $i + 1); // 1
echo $i; // 0

Number post-decrement example

$i = 1;
echo ($i —- + 1); // 2
echo $i; // 0

How about strings (chars)