The Short Answer There are several ways to check if a JavaScript string contains a substring. Here’s a short summary of the most notable ones. 1. string.indexOf() Use the indexOf() method. This method returns the index of the first occurrence of the substring in the string, or -1 if the substring is not found. For …
4 Ways to Check If a String Contains a Substring in JavaScript Read More »
The easiest way to remove a property from an object in JavaScript is by using the delete operator. For example, if you have an object called person with a property age, you can remove the age like this: After you run this code, the person object will no longer have an age property. Note that …
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To find (and not delete) duplicates in a JavaScript array, you can use this function: Example use: Output: To learn how the above approach works, and what alternatives exist, please keep on reading. This guide shows you ways to find array duplicates and show them instead of deleting them. Besides, you will learn what performance …
JavaScript How to Find Duplicates in Array (without Removing) Read More »
The easiest way to check if a JavaScript object is empty is by using the Object.keys to check the length of properties to see if it’s 0. This guide teaches you 5 ways to check if a JavaScript object is empty. Although it only takes one, this is a great chance to learn more about …
To log colored text to the JavaScript console, call the console.log method and include special formatting code %c to colorize the log and pass the colorizing CSS code as the second argument. For example, to log text in red, you can use the %c formatting code, followed by the desired text and a CSS color …
How to Add Colors to JavaScript Console Outputs (Examples) Read More »
An array is one of the key data types in JavaScript. It allows you to store values in a common place where it’s easy to access the values. This is a comprehensive guide to looping through arrays in JavaScript. You will learn multiple different and useful ways in which you can iterate over arrays. Which …
7 Ways to Loop Through an Array in JavaScript (+ One to Avoid) Read More »
In JavaScript, the call() and apply() methods are both used to borrow and call a function on another object. The only difference between them is the way they accept arguments: Both methods are useful when borrowing functionality. To call a function of one object on another object you can use call() or apply(). This is …
JavaScript call() vs apply(): A Complete Guide (Examples) Read More »
To toggle a boolean value in JavaScript, use the not operator (!). This operator negates the boolean value, so if the value is true, it will become false, and if the value is false, it will become true. Here’s an example of how to toggle a boolean: Output: What Is the Not (!) Operator in …
How to Toggle a Boolean in JavaScript (TLDR; bool = !bool) Read More »
In JavaScript the difference between throw Error and throw new Error is that: When it comes to behavior, there’s really no difference between throw Error and throw new Error. For example: But the more technically correct way to throw a new Error object is by using the throw new Error instead of throw Error. Also, …
JavaScript ‘throw new Error’ vs ‘throw Error’ vs ‘throw something’ Read More »
In JavaScript, the bind() method allows you to copy a method from an object. More importantly, you can use the copied method as an independent function but still be able to access the object’s values. Here’s an example that shows how you can use the bind() method: In this example, the greet function is a …
JavaScript bind() Method: A Complete Guide (with Examples) Read More »
