Quickly swap 2 variables in PHP

You can use PHP's `list()`

construct to quickly swap the value of 2 variables. You can also use the short-hand list notation.

```
$a = 2;
$b = 1;
list($a, $b) = [$b, $a];
```

Now `$a`

will hold the value of `$b = 1`

and `$b`

will hold the value of `$a = 2`

.

The `list()`

syntax is a bit outdated now, so you could also use the short-hand notation.

```
$a = 2;
$b = 1;
[$a, $b] = [$b, $a];
```

A `clamp` function for PHP

You can use this function to "clamp" a number between a `min`

and `max`

.

```
function clamp($subject, $min, $max) {
return max($min, min($max, $subject));
}
```

This is perfect for when you need a number to always be within a range, e.g. percentages must be greater than 0 and no more than 100.