Determining if all attributes on a javascript object are null or an empty string

Question

What is the most elegant way to determine if all attributes in a javascript object are either null or the empty string? It should work for an arbitrary number of attributes

Answer 1

Create a function to loop and check:

function checkProperties(obj) {
    for (var key in obj) {
        if (obj[key] !== null && obj[key] != "")
            return false;
    }
    return true;
}

var obj = {
    x: null,
    y: "",
    z: 1
}

checkProperties(obj) //returns false