js 使用Object.defineProperty为对象定义属性

let person = {name:'name',sex:'male'};
Object.defineProperty(person,'age',{value:18});

Object.defineProperty(person,'age',{value:18,enumerable:true});

Object.defineProperty(person,'age',{value:18,writable:true});

Object.defineProperty(person,'age',{value:18,configurable:true});

let number = 18;
Object.defineProperty(person,'age',{
	get() {
		return number;
	},
	set(value) {
		number = value;
	}
});