javascript - JavaScript 基础的简单 "this"问题

Question

var name = 'Mike';
var person = {
  name: 'John',
  welcome: function(){
    var name = 'Mary';
    return 'Hi ' + this.name;
  }
}

//person.welcome(); 
// output is
// Hi John
// I was expecting output to be
// Hi Mary

person.welcome.call();
// output is
// Hi Mike
// In this case since no argument is passed to call so this is window and 
// I get that window.name is Mike

Answer 1

var name = 'Mike';
var person = {
  name: 'John',
  welcome: function(){
    var name = 'Mary';
    return 'Hi ' + this.name;
  }
}

this.name 引用对象属性“name”

name 指的是变量“name”

您将通过 return 'Hi ' + name; 获得预期的结果