有一个简单的方法.只需将对象分配给instance(this)

There have a simple method. Just assign the object to instance(this)

class Model
{
  constructor(obj){
    Object.assign(this, obj)
  }
  print(){
    console.log(this.a);
  }
}

let obj = {a: 'a', b: 'b', c: 'c'}
    
let m = new Model(obj)
console.log(m)
m.print()  // 'a'