Is object empty? [duplicate]

Answer 1

Surprised to see so many weak answers on such a basic JS question... The top answer is no good too for these reasons:

1. it generates a global variable
2. returns true on undefined
3. uses for...in which is extremely slow by itself
4. function inside for...in is useless - return false without hasOwnProperty magic will work fine

In fact there's a simpler solution:

function isEmpty(value) {
    return Boolean(value && typeof value === 'object') && !Object.keys(value).length;
}