Object.assign does not copy correctly

Question

I\'m working with VueJS.

I have a Method that receives a Object as argument.

Then I clone this Object with Object.assign().

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Answer 1

Object.assign only does a shallow copy of the keys and values, meaning if one of the values in the object is another object or an array, then it is the same reference as was on the original object.

var x = { a: 10, b: { c: 100 } };
var y = Object.assign({}, x);

y.a = 20;
console.log( x.a, y.a ); // prints 10 20

y.b.c = 200;
console.log( x.b.c, y.b.c ) // prints 200 200

To deep copy an object, you can using something like the cloneDeep function in lodash or take an uglier approach using built in functions with JSON.parse( JSON.stringify( obj ) ).

Note that the second option will only work with primitive types that are supported by JSON.