ex) 아이스크림, 유제품
function Person(name, first, second){ this.name = name; this.first = first; this.second = second; this.sum = function(){ return this.first + this.second; } }
class Person { constructor(name, first, second){ this.name = name; this.first = first; this.second = second; } sum() { return 'prototype : '+ (this.first + this.second); } }