I prefer Since I don't really have a substantial reason besides aesthetics, I think you and your team should stick with whatever you choose Spread is fantastic when you know beforehand that you're dealing with arrays. Here's what happens:I know some of you are like, duh!

But it is not a preferable choice by the developers and not recommended to use as on large data sets this will work slower in comparison to the JavaScript concat() method.In this example, we will see whether the spread syntax method removes the duplicate elements or not.As we have seen that the spread syntax method helps in merging arrays together but not able to remove duplicate elements from them.In this example, we will see how to get the unique elements in the result or remove duplicate elements from the result.In this example, we have passed our resulted merge array to the JavaScript Set as Sets have the property to remove duplicate elements, but they return set instead of the array.
But, JavaScript arrays are best described as arrays. I like using the Spread operator. So here's the quick rule. Here's what happens:☝️ If we spread our string, it will split the word into separate letters. W3Schools is optimized for learning, testing, and training. The numbers in the table specify the first browser version that fully supports the method. If you know you're dealing with arrays, use spread. Here we discuss three different ways to merge arrays and get the resultant merge array in JavaScript. Except for the "I'm too cool" Internet Explorer - no support there . So if you need IE support, you want to use // ☝when you use push, it returns the LENGTH of the combined array Let's walk through an example.And if we follow the pattern we've been using and used the spread operator. Definition and Usage. THE CERTIFICATION NAMES ARE THE TRADEMARKS OF THEIR RESPECTIVE OWNERS.This website or its third-party tools use cookies, which are necessary to its functioning and required to achieve the purposes illustrated in the cookie policy. In this topic, we will explain the three different ways to merge arrays and get the resultant merge array in JavaScript.This method is used for merging two or more arrays in JavaScript. Arrays are Objects. Also, we will learn how to get the unique elements in the resulted merge array or remove duplicate elements from the resulted merge array. Merge array of objects in efficient way [closed] I have below scenario where I am trying to merge two array of objects.

Both the arrays have unique items.As we have seen, the concat() method merged both the arrays and returns a new array with the result.In this example, we have taken three arrays and have merged them using the JavaScript concat() method. So for example: [ { label: 'private', value: {propa: 'some text', propb: 12}} ] I want the result to merge, so that if the label is the same the properties from the original value get merged with the properties from the new value. If you know you're dealing with arrays, use Anyways I just want to point that out, so you can use the most appropriate method depending on the problem you're trying to solve Also, when you're trying to push an array to another array.

Of course, unless that's what you wanted Spread was introduced in ES6, so all modern browser supports it. This method does not change the existing arrays, but returns a new array, containing the values of the joined arrays.The numbers in the table specify the first browser version that fully supports the method.If you want to report an error, or if you want to make a suggestion, do not hesitate to send us an e-mail: 2 min read. In this example, the job and location has the same property country.When we merged these objects, the result object (remoteJob) has the country property with the value from the second object (location).Merge objects using Object.assign() method. To merge the arrays, I used Lodash _.merge function var result = _.merge(ranking, matches); The output it returned did merge some objects and omitted homogeneous objects. All the arrays have unique elements initially.As we have already seen the syntax of the concat() method that it can merge one or more arrays together. First way. This method does not change the existing arrays, but returns a new array, containing the values of the joined arrays.
So, by using Array. But if you need older browser support, you should use Concat.As you can see, this way of writing it doesn't manipulate or change the existing array.Let's list out both versions, so you can see it in comparison.So now the question is, which one should I pick . The typeof operator in JavaScript returns "object" for arrays. In this example, person[0] returns John: In this topic, we will learn how to merge arrays together in JavaScript. If the array has only one item, then that item will be returned without using the separator. So it doesn't achieve the result we want.BUT, if we follow the concat pattern that we've been doing. And of course as soon as I publish the post I find another great use of the spread operator while I tinker with Babel and React : merging multiple objects' properties into one object!