let a = {};
let b = {
"1": "one",
"2": "two",
"3": "three"
};
let c = {
[42]: "answer",
[7]: "lucky"
let d = {
a: 1,
b: 2,
c: 3
let e = d.a;
let f = d["c"];
let g = {
m() {},
['n'](a) {},
o(a) {
return a;
}
let h = ({}).toString();
let i = {
...d,
a
a?.['b']?.[0]?.(1);