Is there a PHP function for swapping the values of two variables?

Question

Say for instance I have ...

$var1 = \"ABC\"
$var2 = 123

and under certain conditions I want to sw

Answer 1

Yes, there now exists something like that. It's not a function but a language construct (available since PHP 7.1). It allows this short syntax:

 [$a, $b] = [$b, $a];

See "Square bracket syntax for array destructuring assignment" for more details.