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

$a = 'ravi';

$b = 'bhavin';

$a = $b.$a;

$b = substr($a,strlen($b),strlen($a));

$a = substr($a,0,strlen($a)-strlen($b));

echo "a=".$a.'<br/>'.'b='.$b;