Length of an object

function getObjLn(netstructure){
    let ln = 0;
    if (typeof netstructure != 'object') return null;
    for (let key in netstructure){
        ln++;
    }
    return ln;
}

const baseObj = {a: 'null', b: 'string'};

console.log(getObjLn(baseObj));
console.log(Object.keys(baseObj).length);