JavaScript Function Call
Functions are Object Methods
All JavaScript functions are object methods.
If a function is not a method of a JavaScript object, it is a function of the global object (see previous chapter).
The example below creates an object with 3 properties (firstName, lastName, fullName).
Example
var person = {
firstName:"John",
lastName: "Doe",
fullName: function () {
return this.firstName + " " + this.lastName;
}
}
person.fullName(); // Will return "John Doe"
Try it Yourself »
The fullName property is a method. The person object is the owner of the method.
The fullName property is a method of the person object.
The JavaScript call() Method
The call() method is a predefined JavaScript function method.
It can be used to invoke (call) a function with an owner object as the first argument (parameter).
With call(), you can use a method belonging to another object.
This example calls the fullName function of person, but is using it on myObject:
Example
var person = {
firstName:"John",
lastName: "Doe",
fullName: function() {
return this.firstName + " " + this.lastName;
}
}
var myObject = {
firstName:"Mary",
lastName: "Doe",
}
person.fullName.call(myObject); // Will return "Mary
Doe"
