The Ideal Way To Loop Through An Array In JavaScript

“Modern JavaScript provides many ways to iterate or loop through your data”

for loop: For loop is the famous one, and it’s best practice to use it when we know the iterate times for the loop priorly.

while loop: While loop initialization must be outside, before the beginning of the loop, then the loop runs as long as the condition is true.

forEach loop (Method): We use it as a method for an array, it accepts a callback function, and this function runs once for each item in the array. Supports functional programming. More about it is in the sources section.

for…of loop: It is a new version of for loop It is extremely fast when it comes to small data sets, and it performs iteration over JavaScript built-in iterate objects. More about it is in the sources section.

Performance & Use Cases

We don’t have one fits all iteration tool, so:

• In case of very large arrays use traditional for loop.
• In case of medium arrays and need for clean code use while loop.
• In case of supporting functional programming and optimized time forEach is ideal.
• In case of small arrays and for fast iteration use for…of loop.

We’ve only mentioned the most general and famous ones, there are some others that are very useful in some use cases you can search for them.

Sources

https://www.geeksforgeeks.org/what-is-the-fastest-way-to-loop-through-an-array-in-javascript

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for…of

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/while