javascript multiple OR conditions in IF statement

Question

I think I\'m missing something basic here. Why is the third IF condition true? Shouldn\'t the condition evaluate to false? I want to do something where the id is not 1, 2 or

Answer 1

Each of the three conditions is evaluated independently[1]:

id != 1 // false
id != 2 // true
id != 3 // true

Then it evaluates false || true || true, which is true (a || b is true if either a or b is true). I think you want

id != 1 && id != 2 && id != 3

which is only true if the ID is not 1 AND it's not 2 AND it's not 3.

[1]: This is not strictly true, look up short-circuit evaluation. In reality, only the first two clauses are evaluated because that is all that is necessary to determine the truth value of the expression.