原型链

首先做个简单的示例

function People (name){
  this.name = name;
  this.sayName = function(){
    console.log('my name is:' + this.name);
  }
}
People.prototype.walk = function(){
  console.log(this.name + ' is walking');  
}
var p1 = new People('小明');
var p2 = new People('小李');

上面代码原型示意图

1513411452199_2.png