HarmonyOS object.assign实现

function assign<T, U>(target: T, source: U): T & U; 
const target = { a: 1, b: 2 }; 
const source = { b: 4, c: 5 }; 
const returnedTarget = Object.assign(target, source); 
console.log(target);

function assign(target: Record<string, Object>, ...source: Object[]): Record<string, Object> { 
  for (let s of source) { 
    for (let k of Object.keys(s)) { 
      target[k] = Reflect.get(s, k) 
    } 
  } 
  return target 
} 
class D { 
  b: number  
  c: number 
} 
const target: Record<string, Object> = { "a": 1, "b": 2, } 
const source: D = { b: 4, c: 5 } 
const returnedTarget: Record<string, Object> = Object.assign(target, source) 
console.log(target)