Object.defineProperty

Object.defineProperty(obj, prop, {

value: undefined,

enumerable: true,

writable:true,

get: function() {return value},

set: function(newValue) {value = newValue;}

})

当时配置了set和get时，则不能配置value。

Object.getOwnPropertyNames

Object.getOwnPropertyNames(obj)

Object.getOwnPropertyDescriptor

Object.getOwnPropertyDescriptor(obj, prop)

Object.hasOwnProperty(obj, prop)