Jun 10, 2010 · In JavaScript it's not advisable to loop through an Array with a for-in loop, but it's better to use a for loop such as: for(var i=0, len=myArray.length; i < len; i++){} It's optimized as well ("caching" the array length).

Loops can execute a block of code a number of times. Loops are handy, if you want to run the same code over and over again, each time with a different value. Often this is the case when working with arrays: JavaScript supports different kinds of loops: The for statement creates a loop with 3 optional expressions:

Apr 10, 2025 · The for...of statement executes a loop that operates on a sequence of values sourced from an iterable object. Iterable objects include instances of built-ins such as Array, String, TypedArray, Map, Set, NodeList (and other DOM collections), as well as the arguments object, generators produced by generator functions, and user-defined iterables.

Feb 17, 2012 · If you want to loop over an array, use the standard three-part for loop. for (var i = 0; i < myArray.length; i++) { var arrayItem = myArray[i]; } You can get some performance optimisations by caching myArray.length or iterating over it backwards.

Oct 31, 2023 · Now, let's explore the different ways to loop through arrays in JavaScript. How to Loop Through an Array in JS 1. Using the for Loop. The traditional for loop is one of the simplest and most versatile ways to loop through an array. It …

Apr 15, 2025 · The for…of loop is a modern way to loop through arrays in JavaScript. It iterates directly over the values of the array, which makes the syntax more concise and easier to understand compared to the traditional for loop.

Jan 10, 2025 · JavaScript for Loop can be used to iterate over an array. The for loop runs for the length of the array and in each iteration it executes the code defined inside. We can access the array elements using the index number.

The most common ways to loop through an array in JavaScript are the for, for/in and while loops. See how to use them. Examples.

Jun 23, 2022 · How to Loop Through an Array with a forEach Loop in JavaScript. The array method forEach() loop's through any array, executing a provided function once for each array element in ascending index order. This function is known as a callback function.

Aug 3, 2021 · This article focuses on the for loop in the JavaScript programming language and goes over its basic syntax. In addition, I'll explain how to loop through an array using a for loop, which is a fundamental programming concept. What is a for loop? A basic syntax breakdown. A for loop repeats an action while a specific condition is true.