function by(propName) {
return function(a, b) {
    return a[propName] - b[propName];
  }
}
          
const person1 = {name: 'joe', height: 72};
const person2 = {name: 'rob', height: 70};
const person3 = {name: 'nicholas', height: 66};
          
const arr_ = [person1, person2, person3];
          
const arr_sorted = arr_.sort(by('height'));