(JS) handwritten deep copy

JS Hand written deep copy

const obj1 = {
    
	age: 20,
	name: "xxx",
	address: {
    
		city: "earth"
	}
};

/** * * @param obj {Object} */
function deepClone(obj = {
    }) {
    
	// If obj Not an object or empty , Return an empty object directly 
	if (typeof obj !== "object" || obj == null) {
    
		return obj;
	}
	let result;
	// If obj It's the object , Then judge whether it is an array , If it's an array , Then for result Assign to array 
	if (obj instanceof Array) {
    
		result = [];
	} else {
    
		result = {
    };
	}
	// Traverse obj Properties of 
	for(let key in obj) {
    
	// Judge whether it is obj Properties of itself , If so, use recursive assignment to result, It can also be used directly obj[key] assignment , The result remains unchanged. 
		if(obj.hasOwnProperty(key)) {
    
      		result[key] = deepClone(obj[key]);
  }
}
	return result;
}
console.log(deepClone(obj1))