JavaScript Function Call

The call() method is a predefined JavaScript method. It can be used to invoke (call) a method with an owner object as an argument (parameter). This allows borrowing methods from other objects, executing them within a different context, overriding the default value, and passing arguments.

Syntax:

call()

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

JavaScript Function Call Examples

Example 1: In this example, we defines a product() function that returns the product of two numbers. It then calls product() using call() with `this` as the context (which is typically the global object), passing 20 and 5 as arguments. It logs the result, which is 100

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 we defines an object “employee” with a method “details” to retrieve employee details. Using call(), it invokes “details” with “emp2” as its context, passing arguments “Manager” and “4 years”, outputting the result.

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

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

Supported browsers