Check if Javascript Object only contains falsy values

Question

I got an object like this :

var obj1 = {foo: false, bar: ''};
var obj2 = {foo: false, bar: '1'};
var obj3 = {foo: true,  bar: ''};
var obj4 = {foo: true,  bar: '1'};

I want a simple function to check those objects if all of their values are false or not. In this given example only obj1 should trigger a false - cause all of their values are false. obj2, obj3 and obj4 own at least one value which is true.

Is there a simple solution to do this?

Answer 1

As a one-liner:

!Object.keys(obj1).some(function(k) {return obj1[k];});
// Array.some returns true if any callback returns true
// You want true if all return false, aka if none return true
// So just negate Array.some

As a more readable method:

var ok = true, k;
for( k in obj1) if( obj1.hasOwnProperty(k)) {
    if( obj1[k]) {
        ok = false;
        break;
    }
}