-

var handler = {
  get: function (target, name) {
    return name in target ? target[name] : 42;
  },
};
var p = new Proxy({}, handler);
p.a = 1;
console.log(p.a, p.b); // 1, 42

var revocable = Proxy.revocable(
  {},
  {
    get: function (target, name) {
      return "[[" + name + "]]";
    },
  },
);
var proxy = revocable.proxy;
console.log(proxy.foo); // "[[foo]]"

revocable.revoke();

console.log(proxy.foo); //  TypeError
proxy.foo = 1; //   TypeError
delete proxy.foo; //  TypeError
typeof proxy; // "object",   typeof  

Reflect.has(Object, "assign"); // true

Function.prototype.apply.call(Math.floor, undefined, [1.75]);

Reflect.apply(Math.floor, undefined, [1.75]);
// 1;

Reflect.apply(String.fromCharCode, undefined, [104, 101, 108, 108, 111]);
// "hello"

Reflect.apply(RegExp.prototype.exec, /ab/, ["confabulation"]).index;
// 4

Reflect.apply("".charAt, "ponies", [3]);
// "i"

if (Reflect.defineProperty(target, property, attributes)) {
  // 
} else {
  // -   
}