How does if/else work in php?

Question

PHP

There are two variables $firstand $second, containing the values 0​​or 1.

if ( $first OR $second ) {
   // Условие выполняется
} else {
   // Условие не выполняется
}

Common sense (and Google results, by the way, too) tells me that the condition is met EITHER if $first == 1, and $second == 0, or vice versa.
But practice shows that the condition is met even if both variables are equal to one. Those. is executed, not when STRICTLY one of them is equal to one, but IF AT LEAST one.
What's the catch?

Answer 1

no catch: 1 or 1 = 1 , i.e. true .
if you need to strictly check, then use and or xor .