Object.assign

[Sunny]

Object.assign2 = function(target, ...source) {
  let ret = Object(target) 
  source.forEach(function(obj) {
    if (obj) {
      for (let key in obj) {
        if (obj.hasOwnProperty(key)) {
          ret[key] = obj[key]
        }
      }
    }
  })
  return ret
}
const obj1 = {a: 1}
const obj2 = {b: 2}
const res = Object.assign2(obj1, obj2)
console.log(obj1);

[kangkang123269]

function myAssign(target, ...sources) {
  if (target == null) {
    throw new TypeError('Cannot convert undefined or null to object');
  }

  const to = Object(target);

  sources.forEach(source => {
    if (source != null) {
      Object.keys(source).forEach(key => {
        to[key] = source[key];
      });
    }
  });

  return to;
}