CODEWITHSUNDEEP
javascriptarrays
user15178767
user15178767

Reputation: 13

Javascript push array into another array

Is there any difference between the following code(with/without spread operator)?

let result = [];
let arr1 = [1,2,3];

result.push(arr1)
result.push([...arr1])

Upvotes: 0

Views: 57

Answers (1)

CertainPerformance
CertainPerformance

Reputation: 370639

In the first, without spreading, any modifications to the array at the 0th position in result will result in a change to the original arr1 as well, and vice versa.

If you spread the array while pushing, though, such changes will not occur; the two arrays (one in arr1, one in result[0]) will be completely independent.

let result = [];
let arr1 = [1,2,3];

result.push(arr1)

arr1[1] = 999;
console.log(result);

let result = [];
let arr1 = [1,2,3];

result.push([...arr1])

arr1[1] = 999;
console.log(result);

Upvotes: 5

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