函数方法.apply（）.call（）.bind（）

Question

I need help solving this;

let person = {
  firstname: "Benjamin",
  dog: {
    named: "Louie",
    owner: function() {
      return this.named + " is " + this.firstname + "'s dog'";
    }
  }
}

console.log(person.dog.owner.call(person)); // prints undefined is Benjamin's dog' instead of Louie is Benjamin's dog'

I know the call() method will refer to the person object which does not have the property - named.

Is there a way to use the bind() call() or apply() methods to print "Louie is Benjamin's dog'"

Answer 1

Your named key is under dog . So call it this.dog.named

 let person = { firstname: "Benjamin", dog: { named: "Louie", owner: function() { return this.dog.named + " is " + this.firstname + "'s dog'"; } } } console.log(person.dog.owner.call(person)); 

Answer 2

this.named should be this.dog.named because named property is inside dog object.

Check here:

 let person = { firstname: "Benjamin", dog: { named: "Louie", owner: function() { return this.dog.named + " is " + this.firstname + "'s dog'"; } } } console.log(person.dog.owner.call(person)); 

Answer 3

The function requires an object that has a firstname and a named property.

The only way to achieve what you want (without changing that function) would be to create a new object which has them and pass that to one of the functions you mentioned.

console.log(person.dog.owner.call({ firstname: "Benjamin", named: "Louie" }));