Javascript: Cannot copy array and keep them sperate

Asked Feb 19 '20 at 16:53

Active Feb 19 '20 at 16:53

Viewed 25 times

I am so confused. I want to take a and copy its value to b. But when I edit a or b, I do not want it to also edit b and a. Here is an example. When I add 'a' to the a variable, b should still remain as ['b', 'c'] but the console logs says it is ['a', 'b', 'c']. What am I doing wrong?

var a = ['b', 'c'];
var b = a;

a.unshift('a');

console.log(a)
console.log(b)

asked Feb 19 '20 at 16:53

uionut351j

2

It is not a copy, you are referencing it. – epascarello Feb 19 '20 at 16:55
1

have you done this? `var clone = originalArray.slice(0);` – Rick Feb 19 '20 at 16:56
You are referencing your array. Rewrite it to this: ```var b = [...a];```. The spread operator will make a new array and assign the values to it. – Natixco Feb 19 '20 at 16:57
1

Google this: javascript **deep copy.** Consider this page: https://we-are.bookmyshow.com/understanding-deep-and-shallow-copy-in-javascript-13438bad941c – Mike Robinson Feb 19 '20 at 16:59
1

not sure why everyone is repeating all the answers listed in the dupe. lol – epascarello Feb 19 '20 at 17:02

Javascript: Cannot copy array and keep them sperate

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