PHP if OR is the second part checked on true?

Question

I know this must be a simple question, but I know that in PHP in a statement like this

if ($a && $b) { do something }

if $a is false PHP doesn't even check $b

Well is the same thing true about OR so

if ($a || $b) { do something }

If $a is true, does it still check $b

I know this is elementary stuff, but I can't find the answer anywhere... Thanks

Answer 1

Evaluation of logical expressions is stopped as soon as the result is known.

logical operators

Answer 2

See Example 1 on the Logical Operators page in the manual.

// --------------------
// foo() will never get called as those operators are short-circuit

$a = (false && foo());
$b = (true  || foo());
$c = (false and foo());
$d = (true  or  foo());