How many ways to copy object?

Question

How many ways to copy object in javasript and jquery

Sangeetha S · Answer

In JavaScript and jQuery, there are several ways to copy objects. Here are some common methods: JavaScript Using Object.assign() : const original = { a: 1, b: 2 }; const copy = Object.assign({}, original); Using the Spread Operator : const original = { a: 1, b: 2 }; const copy = { ...original }; Using JSON methods (for deep copy, but only for JSON-compatible objects): const original = { a: 1, b: { c: 2 } }; const copy = JSON.parse(JSON.stringify(original)); jQuery Using jQuery's $.extend() : const original = { a: 1, b: 2 }; const copy = $.extend({}, original); Deep copy with $.extend() : const original = { a: 1, b: { c: 2 } }; const copy = $.extend(true, {}, original);

chasetony · Answer

Shallow Copy Methods: Object.assign() const copied = Object.assign({}, original); Copies enumerable own properties from source objects to a target object. Doesn't copy prototype chain or nested objects. Spread Operator const copied = { ...original }; Modern syntax for shallow cloning, equivalent to Object.assign() . Array.prototype.slice() const copiedArray = originalArray.slice(); Array-specific shallow copy method. Array.prototype.concat() const copiedArray = [].concat(originalArray); Alternative array shallow copy method. Manual Property Copy const copied = {}; for (const key in original) { if (original.hasOwnProperty(key)) { copied[key] = original[key]; } } Deep Copy Methods: JSON.parse(JSON.stringify()) const deepCopied = JSON.parse(JSON.stringify(original)); Serialization-based approach. Loses: Functions undefined Symbol properties Circular references Special objects like Date , RegExp structuredClone() const deepCopied = structuredClone(original); Native method (ES2022+) that handles: Circular references Date , RegExp , Map , Set , etc. Preserves data types better than JSON methods Lodash _.cloneDeep() const deepCopied = _.cloneDeep(original); Library implementation with comprehensive type handling. Recursive Copy Function function deepClone(obj, hash = new WeakMap()) { if (obj === null || typeof obj !== 'object') return obj; if (hash.has(obj)) return hash.get(obj); let clone = new obj.constructor(); hash.set(obj, clone); for (const key in obj) { if (obj.hasOwnProperty(key)) { clone[key] = deepClone(obj[key], hash); } } return clone; }

Jignesh Kumar · Answer

Hi Dashrath, We can use below methods, Deep copying Use structuredClone() (latest) _.cloneDeep() (best library) $.extend(true, ...) (if using jQuery) Shallow copies Use { ...obj } Object.assign()

How many ways to copy object?

Answers (3)