HarmonyOS 深拷贝关于list类型如何处理？

function deepCopy(obj: ESObject): ESObject { 
  if (typeof obj !== "object" || obj === null) { 
    return obj; 
  } 
 
  let copy: ESObject; 
  if (Array.isArray(obj)) { 
    copy = []; 
    for (let i = 0; i < obj.length; i++) { 
      copy[i] = deepCopy(obj[i]); 
    } 
  } else { 
    copy = {}; 
    for (let i = 0; i < obj.length(); i++) { 
      let key:ESObject=obj[i]; 
      if (obj.hasOwnProperty(key)) { 
        copy[key] = deepCopy(obj[key]); 
      } 
    } 
  } 
  return copy; 
} 
let arr1:Array<number> = new Array<number>(1, 2, 3); 
let arr2:Array<number> = deepCopy(arr1); 
arr2[2] = 4; 
 
console.log('arr1: '+String(arr1)); 
console.log('arr2: '+String(arr2));