JavaScript

In JavaScript, closure means an inner function can access variables that belong to the outer function. More importantly, this is possible even after the execution of the outer function. This article is split into two sections: In the quick explanation, you are going to learn how closures work in a nutshell with examples. In the […]

To remove a specific element from an array in JavaScript: For instance: Output: However, this only removes the first occurrence of the specific element! To remove all occurrences of the specific element, you need to use a loop. For example, let’s remove all 3s from an array of numbers: Output: And yes, this is the

In JavaScript, you can have if-else statements on one line. To write an if-else statement on one line, follow the ternary conditional operator syntax: For example: This is a useful way to compress short and simple if-else statements. It makes the code shorter but preserves the readability. However, do not overuse the ternary operator. Converting

To comma-separate thousands in a big number in JavaScript, use the built-in toLocaleString() method. It localizes the number to follow a country-specific number formatting. To separate thousands with commas, localize the number to the USA. To do this, pass the ‘en-US’ locale code as an argument to the toLocaleString() method. For example: Output: Alternative Approaches

To export multiple functions in JavaScript, use the export statement and export the functions as an object. For example: Alternatively, you can use the export statement in front of the function definitions. This exports the function in question automatically and you do not need to use the export statement separately. For instance: This is the

Commonly you see the Uncaught TypeError: cannot set property innerText of null error if you try to access an HTML element on a page before it appears. The solution. Move your JavaScript from the head to the body tag below the HTML element you are trying to access. An Example Situation Let’s say you are

To ask for user input in JavaScript, use the built-in window.prompt() method. For example: This shows the following modal at the top of your page: Prompt Box in JavaScript To ask for user input in JavaScript, you can use the built-in prompt box. To show a prompt, use the prompt() method. This method takes two

The difference between undefined and undeclared variables in JavaScript is: This is a comprehensive guide to understanding the differences between undefined and undeclared in JavaScript. Examples The best way to understand the difference between undefined and undeclared in JavaScript is by having a look at examples. Example 1: Undefined Variable To see an example of

In JavaScript, there are three types of popup boxes: Here is the syntax for using each of them: This is a complete guide to popups in JavaScript. You will learn how and why to use the three different popup types in JavaScript. The guide shows you simple and illustrative examples. JavaScript Popup Modals Here is

To limit decimal places in JavaScript, use the toFixed() method by specifying the number of decimal places. This method: For instance, let’s round to 2 decimals: Output: But this is just one way to do it. Also, it has some caveats. This is a comprehensive guide to rounding values in JavaScript. You will learn how