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

Check all values with Object.values. It returns an array with the values, which you can check with Array.prototype.every or Array.prototype.some:

const isEmpty = Object.values(object).every(x => x === null || x === '');

const isEmpty = !Object.values(object).some(x => x !== null && x !== '');

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