Since ES6, we can define a callback function as an arrow function: const ages = Finally, the thisValue (optional) parameter will be utilized as the value of this in the callback.Īlternatively, you could define the callback function somewhere outside the forEach() method and call it using the following syntax: const ages = īoth of those are pretty readable and neat ways to use a forEach() method, but we can simplify the syntax furthermore. This callback function takes three arguments - the currentElement (required), its index (the index of the currentElement), and the array ( arr) to which the element belongs. The forEach() method has a very straightforward syntax: forEach(callback(currentElement, index, arr), thisValue) Īs a parameter, it accepts a callback function and runs it for each entry in the array. We'll also compare the forEach() method and for loop so you can differentiate between two of them and know when to choose one over the other. In this guide, you'll learn how to use the forEach() method and how it works using actual code examples.

It has the distinct qualities that set it apart from other techniques of iterating over arrays, meaning it's up to you to select which method to employ based on what you're doing. The forEach() method is one of many that can be used to loop through the contents of an array and show each element successively.

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