Logical Operators: || versus or

In the realm of programming, logical operators play a crucial role in controlling the flow of execution. Among these operators, || and or are often used to evaluate boolean expressions and produce a result. But which one should you choose?

As a general rule, || is considered more common and is usually preferred. This preference stems from its higher precedence over the or operator. Precedence determines which operator is evaluated first in an expression. In PHP, || has a higher precedence than or.

Consider the following code snippets:

$e = false || true; // Result: true
$f = false or true; // Result: false

In the first case, || acts like ($e = (false || true)), and $e is assigned the value of the expression. In the second case, or acts like (($f = false) or true), and $f is assigned false before the true operand is evaluated, resulting in false being assigned to $f.

Thus, when you need an OR operation to work like you would expect it to, using || is generally recommended. Its higher precedence ensures that it is evaluated before other operators, preventing unexpected assignments like in the case of or.