Found 9054 Articles for Front End Technology

This tutorial will teach us to use the JavaScript functions as an object. However, functions, objects, and arrays are the mutable data types in JavaScript, and all mutable data types are the objects.The JavaScript object is one type of entity that contains the key-value pairs. It contains unique keys; every key has some values that can be of any type. We can use the object key to access the values of the objects.We can create a function so that it behaves like an object. Below, we have given a detailed explanation of converting the function to an object.Use JavaScript function ... Read More

In this tutorial, we will learn to assign a function to a variable in JavaScript. The function is the code block that we can reuse quickly, often just by making a function call. There are two ways to declare a function in JavaScript, one is a named function, and another is an anonymous function.Most JavaScript programmers are familiar with the name function, and users can follow the below syntax to declare the named function.function function_name() { //function body }In the above syntax, users can see that, we can create a function definition with the function keyword and following by function ... Read More

In this tutorial, we will learn how to invoke a JavaScript Function as a method. In JavaScript, the code inside a function will execute when the function is invoked. We can invoke a function in a variety of ways. One of them is using the method. The method is a property of an object that has a function value. We can define functions as object methods. This function will have a function name, a parameter (optional), and a return type (optional). It will have a "this" keyword which refers to an object. Users can follow the syntax below to declare ... Read More

In this tutorial, we will learn how to invoke a JavaScript Function as a function. Functions are a set of reusable codes that perform a specific task and may return a value. In JavaScript, functions are defined by the keyword function. A function has different parts, like a function name, parameter list, function body, and return statement. A function may not have any parameters and may also not have any return statement. In JavaScript, we also have functions with no function names, called anonymous functions. Users can follow the syntax below to declare a function. // function declaration function function_name(parameter1, ... Read More

JavaScript does not support Function Overloading. The following shows function overloading − function funcONE(x,y) { return x*y; } function funcONE(z) { return z; } The above will not show an error, but you won't get desired results. On calling, // prints 5 funcONE(5); // prints 5, not 30 funcONE(5,6); JavaScript does not support function overloading natively. If we will add functions with the same name and different arguments, it considers the last defined function.

Default ParametersThe default parameter came to handle function parameters with ease. You can easily set Default parameters to allow initializing formal parameters with default values. This is possible only if no value or undefined is passed. Example Live Demo                    // default is set to 1          function inc(val1, inc = 1) {             return val1 + inc;          }                    document.write(inc(10, 10));          document.write("");          document.write(inc(10));   ... Read More

Functions and methods are the same in JavaScript, but a method is a function, which is a property of an object.The following is an example of a function in JavaScript −function functionname(param1, param2){    // code }ExampleThe method is a function associated with an object. The following is an example of a method in JavaScript − Live Demo                    var employee = {             empname: "David",             department : "Finance",             id : 002,             details : function() {                return this.empname + " with Department " + this.department;             }          };          document.write(employee.details());           Output

To return an object from a JavaScript function, use the return statement, with this keyword.ExampleYou can try to run the following code to return an object from a JavaScipt function − Live Demo                    var employee = {             empname: "David",             department : "Finance",             id : 002,             details : function() {                return this.empname + " with Department " + this.department;             }          };          document.write(employee.details());           Output

The custom functions in JavaScript are user-defined functions. JavaScript allows us to write our own functions. The following is the syntax −Syntax     Bult-in functions are functions already provided by JavaScript library, for example, the following are string functions −S. NoMethod & Description1charAt()Returns the character at the specified index.2charCodeAt()Returns a number indicating the Unicode value of the character at the given index.3concat()Combines the text of two strings and returns a new string.4indexOf()Returns the index within the calling String object of the first occurrence of the specified value, or -1 if not found.ExampleThe following is an example of a built-in ... Read More

Compared to other languages, JavaScript works differently, especially if you get confused between function and methods. In this tutorial, we will learn whether JavaScript functions are object methods. The example written in this tutorial gives you a better idea about the differences and which one is more convenient for us. What are JavaScript Functions? Functions are generally used to define a particular task that we want to perform. It is a set of instructions, and every function has its block of code. Functions can also have parameters by performing desired operations on those parameters. Syntax The syntax for the ... Read More