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JavaScript - modifying object copy causes the original object change
1 answers
0 points
Why is modifying copy of an object causing the original object change?
My code:
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const object1 = { a: 1 };2
const object2 = object1;3
4
object2.a = 2;5
6
console.log(object1.a); // 2 instead of 1 1 answer
0 points
You've misunderstood the statement: var object2 = object1.
In JavaScript, objects are passed and assigned by reference, so object1 and object2 are references pointing to the same object.
Solution
To avoid it, you can create a copy of the object:
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const object2 = Object.assign({}, object1);Full example:
xxxxxxxxxx1
const object1 = { a: 1 };2
const object2 = Object.assign({}, object1);3
4
object2.a = 2;5
6
console.log(object1.a); // 17
console.log(object2.a); // 2
See also
References
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