for in loops over enumerable property names of an object. for of (new in ES6) does use an object-specific iterator and loops over the values generated by that. In your example, the array iterator does yield all the values in the array (ignoring non-index properties).

Dec 29, 2014 · for (... in ...) is typically used to iterate through the properties of objects (which are what javaScript uses for associative arrays), while the typical for loop is used for sequential arrays.

Nov 20, 2024 · The JavaScript for-in loops through the enumerable properties of an object. The loop will iterate over all enumerable properties of the object itself and those the object inherits from its constructor’s prototype.

Aug 3, 2012 · It depends on what you need. I usually use for-in loop because it is a shorter form, but sometimes you may want to have control over the iteration variable. For instance, if you want to iterate over even indices, you'd need to use the normal for loop: for (var i = 0; i < myarray.length; i+=2) {...}

Feb 20, 2019 · Generally, for/of is the most robust way to iterate over an array in JavaScript. It is more concise than a conventional for loop and doesn't have as many edge cases as for/in and forEach().

Feb 4, 2021 · In this article, I am explaining the differences between the four for loops in JavaScript. The best use for these loops is as follows: For arrays, use for...of (or forEach). If you work...

We have the for..of loop for collections (like arrays) and then we have the for..in loop for objects. Since objects in JavaScript are basically just a collection of keys and values, we can loop over the properties which can be really useful.

In this in-depth exploration, we’ve dissected the differences between JavaScript’s for…in, for…of, and forEach loops. Understanding when and how to use these loops is essential for efficient coding and data manipulation in JavaScript.

Aug 13, 2024 · for..in iterates over all enumerable property keys of an object. for..of iterates over the values of an iterable object. Examples of iterable objects are arrays, strings. Often I do forget the...

Learn the key differences between for...in and for...of loops in JavaScript, including their syntax, use cases, and examples.