【继承】构造函数继承

patterns-inheritance-constructor.js

function SuperClass(id) {
  this.id = id;   
  this.books = ['a' ,'b', 'c'];
}

SuperClass.prototype.showBooks = function () {
  console.log(this.books);
}

function SubClass (id) {
  SuperClass.call(this, id);
}

var instance1 = new SubClass(10);
var instance2 = new SubClass(11);

instance1.books.push('d');
console.log(instance1.books); // ['a' ,'b', 'c', 'd']
console.log(instance1.id); // 10
console.log(instance2.books); // ['a' ,'b', 'c']
console.log(instance2.id); // 11

instance1.showBooks(); // TypeError