How do you copy properties from one object to other?
Interviewer Expectations for this Question
01
Core Competency
Assesses fundamental understanding of JavaScript conventions, runtime behavior, and memory/performance considerations.
02
Evaluation Criteria
Hiring managers look for precision, avoidance of ambiguous jargon, and ability to explain trade-offs under real production conditions.
Comprehensive Model Answer
Verified Solution
You can use the Object.assign() method which is used to copy the values and properties from one or more source objects to a target object. It returns the target object which has properties and values copied from the source objects. The syntax would be as below,
Object.assign(target, ...sources);
Let's take example with one source and one target object,
const target = { a: 1, b: 2 };
const source = { b: 3, c: 4 };
const returnedTarget = Object.assign(target, source);
console.log(target); // { a: 1, b: 3, c: 4 }
console.log(returnedTarget); // { a: 1, b: 3, c: 4 }
As observed in the above code, there is a common property(b) from source to target so it's value has been overwritten.
Candidate Response Strategy & Interview Tips
- Start with a concise one-sentence summary: Deliver a direct, confident answer first before expanding into nuances.
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