Dec 9, 2008 · There are a couple of ways to append an array in JavaScript: 1) The push() method adds one or more elements to the end of an array and returns the new length of the array.

So, we are going to push an object (maybe empty object) into that array. myArray.push({}), or myArray.push({""}). This will push an empty object into myArray which will have an index number 0, …

I have a JavaScript array dataArray which I want to push into a new array newArray. Except I don't want newArray[0] to be dataArray. I want to push in all the items into the new array: var newArra...

May 9, 2016 · Best thing with concat is it will return a reference to the resulting array. So it's perfect to use it in functional programming and chaining. Array.prototype.concat() is my preference. 4) A new …

Apr 29, 2014 · Are there any substantial reasons why modifying Array.push() to return the object pushed rather than the length of the new array might be a bad idea? I don't know if this has already been …

He wants to push to existing array so Array.prototype.push.apply(arr1, arr2) is the correct answer, because using arr1.concat(arr2) you are creating a new array.

Feb 14, 2021 · Does JavaScript simply create a new Array with added element and point the variable I've already assigned to to the new Array or something else?

Apr 19, 2016 · Array.push () and unique items Asked 9 years, 10 months ago Modified 1 year, 8 months ago Viewed 252k times

Jun 15, 2017 · Why does a return of the push method cause Uncaught TypeError: acc.push is not a function But a return concat results in the correct solution? [1, 2, 3, 4].reduce(function name(acc, …

Jan 1, 2010 · For an array of strings (but not an array of objects), you can check if an item exists by calling .indexOf() and if it doesn't then just push the item into the array: