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JavaScript Object-Oriented JavaScript (2015) Introduction to Methods Understanding this

Sonja Tomcic
Sonja Tomcic
6,590 Points
Posted by Sonja Tomcic
Sonja Tomcic
6,590 Points

i've tried this a couple of times, but I don't know how to do this

can someone help me?

object.js 
var contact = {
  fullName: function() {
    var firstName = "Andrew";
    var lastName = "Chalkley";
    console.log(firstName + " " + lastName);
  }
}

1 Answer

Erik Nuber
Erik Nuber
20,629 Points
Erik Nuber
Erik Nuber
20,629 Points 
var contact = {
  firstName : "Andrew",
  lastName : "Chalkley",
  fullName: function() {
    console.log(this.firstName + " " + this.lastName);
  }
}

You have firstName and lastName outside of the fullName function, so when referenced with just their name the function will not be able to find them because they are not inside of it anymore. By using the keyword "this" you can access other properties on the object you are currently inside which happens to be the contact object.