If you’re new to programming with JavaScript, you may be wondering what a method is. In short, a method is a function that belongs to an object. In this article, we’ll take a closer look at methods in JavaScript, including how to create and call them.
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Introduction
A method is a function that is stored as a property of an object. In JavaScript, every object has a special property called prototype. The prototype property of an object is where you put methods and properties that you want all instances of that object to have.
What is a method?
In JavaScript, a method is a function that is associated with an object. You can call a method on an object to invoke the function that it defines. For example, you can use the push() method to add an element to an array.
Defining methods
A method is a function that is associated with an object or class. In JavaScript, you define methods as functions attached to an object. You can also define methods as standalone functions, but they are not associated with any particular object.
Methods are generally used to perform some action on the data held by an object or to calculate something based on that data. For example, you could define a method to calculate the monthly payments on a loan, based on the loan’s interest rate and duration. You could also define a method to display a greeting message, based on the user’s name.
Methods are invoked (called) using the () operator. When you invoke a method, you can pass in some data (known as arguments) which will be used by the method. The data type of the arguments and the return value of the method must be specified when the method is defined.
Calling methods
Methods are functions that are attached to objects. In JavaScript, all objects have a built-in method called toString(). This returns a string representation of the object, which is useful for debugging:
let obj = {};
console.log(obj.toString()); // [object Object]
You can also define your own methods. Here’s a simple example of a method that increments a number:
let counter = 0;
function increment() {
counter++;
}
increment(); // 1
increment(); // 2
The this keyword
The this keyword is used to refer to the current instance of an object. In other words, it is a reference to the object that is executing the current function.
In the following example, the this keyword refers to the global object:
function myFunction() {
console.log(this);
}
myFunction(); // Outputs: [object Window]
If you use strict mode, however, the this keyword will not refer to the global object:
function myFunction() {
‘use strict’;
console.log(this);
}
Conclusion
In JavaScript, a method is a function that is attached to an object. Methods are used to perform various tasks, such as calculate the sum of two numbers, fetch data from a server, or format a string.
There are many built-in methods in JavaScript, such as `toString()`, which converts a value to a string, or `split()`, which splits a string into an array of substrings. In addition to these built-in methods, you can also create your own custom methods.
When creating a custom method, you first need to create a function. This function will contain the code that you want to execute. Once you have created your function, you then need to attach it to an object using the `prototype` property. For example:
“`js
function myFunction() {
// code goes here!
}
MyObject.prototype.myFunction = myFunction;
“`
