Question

In the fun function, I want to return 1 if the boolean expression is true.

function fun() {
    (1 == 1) && return 1;
}

alert(fun());

​Of course, I can easily do this with if (1 == 1) return 1. However, I am wondering why the above code does not work. It triggers a “Uncaught SyntaxError: Unexpected token return” error in the console in Chrome.

Shouldn’t return 1 only run if (1 == 1) is true? Why does this not work?

Answer 1

It doesn’t work because the && operator needs expressions for both of its operands. E.g.,

expr1 && expr2

return statements, however, are not (grammatically speaking) expressions.