Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Articles by Shubham Vora
Page 33 of 80
How to pass the value 'undefined' to a function with multiple parameters in JavaScript?
In this tutorial, we will learn how to pass the value 'undefined' to a function with multiple parameters in JavaScript. In JavaScript, the data type of 'undefined' is primitive. When a variable is declared, JavaScript automatically assigns the value 'undefined' to it. If a function has multiple parameters and one of the parameters' values is not available at the moment, then we need to omit that parameter's value from the function call. But if we omit the parameter's value with a blank space, the JavaScript will show an error. The Problem function abc(param1, param2, param3) { ...
Read MoreCan I declare JavaScript variables as specific types?
In this tutorial, we will explore whether JavaScript variables can be declared with specific types. JavaScript contains three reserved keywords to declare variables: let, var, and const. When declaring variables, each keyword has different scope behavior. Variables declared with const remain constant and cannot be reassigned after initialization. Variables declared with let have block scope and cannot be accessed outside their scope. Variables declared with var can have global or function scope. Syntax let var1 = value; var var2 = value; const var3 = value; JavaScript is dynamically typed, meaning you don't need to ...
Read MoreHow do I empty an array in JavaScript?
This tutorial teaches us to make an array empty in JavaScript. While programming with JavaScript, programmers need to make an array empty in many conditions. For example, coders are doing competitive programming with JavaScript. Suppose, to solve some problem, they need to create a new or an empty array while calling the function every time. Users can visualize this problem from the below example. function child() { // create a new array or use a single array and make it empty every time function invokes } function parent() { ...
Read MoreHow can I check whether a variable is defined in JavaScript?
In JavaScript, checking whether a variable is defined helps prevent ReferenceError exceptions. A variable can be declared but undefined, declared and defined, or completely undeclared. Understanding the difference between these states is crucial: const data = 10; // declared and defined (initialized with value 10) let data; // declared but undefined const data = null; // declared and defined (initialized with null) data = 10; // undeclared but assigned (creates global variable) data ...
Read MoreHow to pass JavaScript Variables with AJAX calls?
In this tutorial, we will learn how to pass JavaScript Variables with AJAX calls. AJAX stands for Asynchronous JavaScript and XML. As the name suggests, it performs asynchronous operations on your web page. AJAX communicates with the server by HTTP requests and gets the required data as an HTTP response. We can control these HTTP requests by passing the JavaScript variables with AJAX calls. There are various types of HTTP requests, and in this tutorial, we will discuss the most popular HTTP requests by using AJAX and also pass JavaScript variables with it. Pass JavaScript Variables with ...
Read MoreHow to prevent duplicate JavaScript Variables Declaration?
In this tutorial, we will look at a few ways to prevent duplicate JavaScript variable declarations and comparison between them from understanding which one is suitable in a given context. The best way to prevent duplicate variable declaration is to avoid creating global variables. Let's move forward to discuss this. Wrapping Code Within a Function Here, the variables declared inside the function are not accessible outside the function and vice versa. Users can follow the syntax below for using this method. Syntax (function(){ var varName = "test"; }()) ...
Read MoreHow can I check if a JavaScript variable is function type?
In this tutorial, we will learn different approaches to checking if a JavaScript variable is of function type or not. In JavaScript, functions contain blocks of code that improve code reusability. There are mainly two ways to declare functions: named functions and anonymous functions. When declaring anonymous functions, we need to store them in variables to access and call them later. Here's how to declare an anonymous function and store it in a variable: let tutorialspoint = function() { // code for the function } As you can see, ...
Read MoreWhat characters are valid for JavaScript variable names?
In JavaScript, variable names must follow specific rules to be valid. Understanding these rules helps you write error-free code and follow good naming practices. Variables store values that can be accessed and modified throughout your program. The variable name acts as an identifier to reference the stored value. Basic Rules for Variable Names Must start with a letter (a-z, A-Z), dollar sign ($), or underscore (_). Cannot start with a number. After the first character, can contain letters, numbers (0-9), dollar signs, or underscores. Variable names are ...
Read MoreHow to check for null, undefined, or blank variables in JavaScript?
In JavaScript, checking for null, undefined, or blank variables is a common task. There's no single built-in function to check all these states, but we can use operators like typeof and equality operators to handle each case effectively. Let's first understand the differences between these variable states: Null vs Undefined vs Blank Undefined variable − A variable that has been declared but not assigned a value, or a variable that doesn't exist. Null variable − A variable that has been intentionally assigned the value null to represent "no value". Blank variable − Usually refers to empty ...
Read MoreHow do I Create Dynamic Variable Names Inside a JavaScript Loop?
Creating dynamic variable names inside a JavaScript loop means generating variable names programmatically during runtime rather than hardcoding them. This technique is useful when you need to create multiple variables based on user input, API responses, or iterative patterns. In this article, we'll explore four different approaches to create dynamic variable names inside a JavaScript loop, with practical examples and best practices. Approaches to Create Dynamic Variable Names Here are the four main approaches we'll cover, each with different use cases and considerations: Using Array Using eval() ...
Read More