//방법1
객체.키
//방법2: 변수를 키값으로 조회
let a = "name"
Obj.[a]
let a_dict = {name:'Juhee',age:26}
a_dict['name'] //'Juhee'
//방법1
Obj.키 = "값"
//방법2
a_dict['height'] = 170
a_dict //{'name':'Juhee','age':26,'height':170}
delete.Obj.키
names = [{'name':'bob','age':20},{'name':'carry','age':38}]
names[0]['name'] //'bob'