How can I merge two objects in JavaScript?

How can I merge two objects in JavaScript?

You can use the Object.assign() method or the spread operator to merge two objects. For example:

// Using Object.assign() const obj1 = { a: 1, b: 2 }; const obj2 = { b: 3, c: 4 }; const merged = Object.assign({}, obj1, obj2);

// Using spread operator const mergedWithSpread = {...obj1, ...obj2};

Both will result in { a: 1, b: 3, c: 4 }.

What happens if there are duplicate keys?

If there are duplicate keys, the values from the second object will overwrite the values from the first object. In the previous example, the value of 'b' in obj2 (which is 3) overwrites the value of 'b' in obj1 (which is 2).

Can I merge more than two objects?

Yes, you can merge multiple objects using both Object.assign() and the spread operator. Just pass all the objects you want to merge as arguments.

Are there any performance considerations?

For small objects, performance is usually not an issue. However, for larger objects or deep merging, consider using libraries like Lodash for better performance.