Array push creates a new Array which I am instead just looking to add a record to my original data

Question

I want to add an element to my array, but push just adds a new array

var original = [{"Member_Name":"MORGAN, KATHY","Member_ID":"308484402","Member_DOB":"03/05/1998","ProgramType":"Supportive","RateCode":"000603"},{"Member_Name":"BUDZYNSKI, ALDA","Member_ID":"C436418737","Member_DOB":"11/30/1998","ProgramType":"Supportive","RateCode":"000603"},{"Member_Name":"MALLARI, SCOTT","Member_ID":"705681684","Member_DOB":"08/20/2002","ProgramType":"Supportive","RateCode":""}]

let newData = {name:"John", address:"432 main st"}; 
//let newData = [{"name":"John", "address":"432 main st"}]; 

const arr = [];
arr.push(original)
arr.push(newData)

console.log(arr);

Does this answer your question? [How to extend an existing JavaScript array with another array, without creating a new array](https://stackoverflow.com/questions/1374126/how-to-extend-an-existing-javascript-array-with-another-array-without-creating) — Clarity, Dec 02 '19 at 18:21
Well, working with just numbers ends being different to me as I end up being distracted from looking at my actual objects and strings of data that I was getting a nested nightmare . I'm sure that answer if helpful to some, just not to me thx though — , Dec 02 '19 at 18:27

score 3 · Answer 1 · answered Dec 02 '19 at 18:19

3

You can't push an array to another array using push - JavaScript will just assume you meant to add the array as an element, rather than concatenating the array.

You'll want to use forEach:

const arr = [];
original.forEach(el => arr.push(el));
arr.push(newData);

Alternatively, you can use the array-spread operator:

const arr = [...original, newData];

Finally, you could use concat.

const arr = original.concat([newData]);

answered Dec 02 '19 at 18:19

Dan

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note that `array.push` can also take a variable number of arguments, so you could do `arr.push(...original, newData);` – Andrew Ault Dec 02 '19 at 18:22
Huh! TIL. Every day is a school day – Dan Dec 02 '19 at 18:22

score 0 · Accepted Answer · answered Dec 02 '19 at 18:21

If i understand correctly, you are trying to merge arr and original ?
In that case, you can use concat().

var original = [{test: 'value'}]

let newData = {name:"John", address:"432 main st"}; 
//let newData = [{"name":"John", "address":"432 main st"}]; 

let arr = [];
arr = arr.concat(original)
arr.push(newData)

console.log(arr);

score 0 · Answer 3 · answered Dec 02 '19 at 18:22

This is because you are creating 2 separate Arrays. const arr = [] and var original = [...] . And then you push original into arr, which creates the behaviour you don't want.

You dont need the const arr - you can just push newData into original

original.push(newData)

If you want to create another one then you can just use the spread operator.

const arr = [...original, newData];

score 0 · Answer 4 · answered Dec 02 '19 at 18:24

0

Use array-Spread Operator

const arr =[...original,newData];

answered Dec 02 '19 at 18:24

Fazeel Ahmed

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Array push creates a new Array which I am instead just looking to add a record to my original data

4 Answers4