How to "push' a new item to the middle of an array?

Question

I just completed section1, and noticed that there isn't a method covered on how to push an item to the a specific location of the array. For example, if I wanted the array to show

var suits = ["hearts","clubs","Brooks Brothers", "diamonds","spades"]

How would I be able to push in "Brooks Brothers" into the position [2] of the array suits, and shift the rest 1 down? Is there a built-in function in javascript similar to push that would enable me to do this?

I suppose I could always, with some diffculty:

function add (item, position){
    var length = suits.length;
    for(i = length -1; i >= position; i--){
        suits[length] = suits[i];
        length--;
    };
    suits[position] = item;
};

add("Brooks Brothers",2) //to add it to the middle

This seems to be Javascript and not Java (or PHP). – Kayaman Jan 08 '18 at 06:46 — Kayaman, Jan 08 '18 at 06:46
You want to insert element or interchange....? – GYaN Jan 08 '18 at 07:01 — GYaN, Jan 08 '18 at 07:01

CodeIt · Answer 1 · 2020-10-05T17:41:23.070

30

There are no inbuilt function for this in JavaScript but you can simply do this using splice

var suits = ["hearts", "clubs", "Brooks Brothers", "diamonds", "spades"];

suits.splice(2, 0, "Brooks Brothers");

console.log(suits);

This would insert item X to index 2 of array suits, ["hearts", "clubs", "Brooks Brothers", "Brooks Brothers", "diamonds", "spades"]

Syntax

<array-name>.splice(<position-to-insert-items>,0,<item-1>,<item-2>,..,<item-n>)

Always pass second second argument as 0, because we don't want to delete any item from the array while splicing.

edited Oct 05 '20 at 17:41

answered Jan 08 '18 at 06:48

CodeIt

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> "There are no inbuilt function for this in JavaScript" -- I believe that's a false statement, because `splice` *is* an inbuilt function in JS, and it does exactly what's being asked; right? – Drakinite Jul 20 '22 at 19:05
1

OP wants to push a new item to the middle of the array. There is no built function for that exact purpose. It is possible using splice, but then we will have to specify position to insert item. – CodeIt Jul 21 '22 at 16:59
1

"...and noticed that there isn't a method covered on how to push an item to the a specific location of the array". Specifying the insert position is exactly in the question and `splice(idx, 0, elem)` does exactly that. You had exactly what OP needed, no buts. – Drakinite Jul 23 '22 at 01:31

score 14 · Answer 2 · answered Jan 08 '18 at 06:50

14

You can use Array.splice in order to insert item to Array at specific place.

const suits = ["hearts", "clubs", "Brooks Brothers", "diamonds", "spades"];

suits.splice(2, 0, 'newItem');

console.log(suits);

answered Jan 08 '18 at 06:50

felixmosh

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score 6 · Answer 3 · answered Jan 08 '18 at 06:51

You can use the built-in Splice Function

The splice() method changes the contents of an array by removing existing elements and/or adding new elements.

1- To insert single value

var suits = ["hearts","clubs","Brooks Brothers", "diamonds","spades"];

//1st param is insert index = 2 means insert at index 2
//2nd param is delete item count = 0 means delete 0 elements
//3rd param is new item that you want to insert
suits.splice(2, 0 , "Test");

console.log(suits);

2- To insert array into your suits array

var suits = ["hearts","clubs","Brooks Brothers", "diamonds","spades"];

var newSuitsToInsert = ["test1", "test2","hello"];

    //1st param is insert index = 2 means insert at index 2
    //2nd param is delete item count = 0 means delete 0 elements
    //3rd param is new item that you want to insert
    //... is the spread syntax which will expand elements as one
    suits.splice(2, 0 , ...newSuitsToInsert);

    console.log(suits);

score 2 · Answer 4 · answered Jan 08 '18 at 06:50

You should use splice function

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert).

var suits = ["hearts","clubs","Brooks Brothers", "diamonds","spades"]

suits.splice(2, 0, "somevalue");

console.log(suits);

How to "push' a new item to the middle of an array?

4 Answers4