JavaScript Function Call

The Javascript Function call is a predefined javascript method, that is used to write methods for different objects. It calls the method, taking the owner object as an argument. The keyword this refers to the “owner” of the function or the object it belongs to. All the functions in javascript are considered object methods. So we can bind a function to a particular object by using ‘call()’. A function will be the global object if the function is not considered a method of a JavaScript object.

Syntax:

call()

Return Value: It calls and returns a method with the owner object being the argument.

Example 1: Here is a basic example to describe the use of the call() method. 

Javascript

// function that returns product of two numbers
function product(a, b) {
    return a * b;
}

// Calling product() function
let result = product.call(this, 20, 5);

console.log(result);

Output:

100

Example 2: This example describes the use of function calls with arguments.

Javascript

let employee = {
    details: function (designation, experience) {
        return this.name
            + " "
            + this.id
            + designation
            + experience;
    }
}

// Objects declaration
let emp1 = {
    name: "A",
    id: "123",
}
let emp2 = {
    name: "B",
    id: "456",
}
let x = employee.details.call(emp2, "Manager", "4 years");
console.log(x);

Output:

B 456
Manager
4 years

Example 3: This example describes binding a function to an object.

Javascript

let obj = { a: 12, b: 13 };
function sum() {
    return this.a + this.b;
}
console.log(sum.call(obj));

Output:

25

We have a complete list of Javascript Functions, to check those please go through the Javascript Function Complete reference article.

Supported Browser:

• Google Chrome 1.0
• Firefox 1.0
• Microsoft Edge 12.0
• Internet Explorer 5.5
• Opera 4.0
• Safari 1.0