Incrementing / Decrementing a Number by a Number with PHP
We've previously discussed how to simply increment and decrement a variable but that only covered incrementing by a value of 1. What about when you want to increment a variable by 5s? There's a few different ways this can be accomplished. First, the obvious (albeit far from ideal) using ++ 5 times:
$i = 0;
$i++;
$i++;
$i++;
$i++;
$i++;
echo $i; // 5!
I know, that's silly, but I'm sure someone out there has done it before. Now let's get serious, to increment a variable by 5 you can use +=, which is similar to ++ but allows you specify the value to increment by:
$i = 0;
$i += 5;
echo $i; // Still 5!
Decrementing works in quite the same way but, you guessed it, uses -= instead:
$i = 10;
$i -= 5;
echo $i; // 5, yet again!
The use of += and -= is the shorthand equivalent of the following syntax:
$i = $i + 5;
$j = $j - 5;If you ever run into (or already have run into) the first example of multiple ++ or --s please please please leave a comment below!