📅  最后修改于: 2022-03-11 15:03:53.239000             🧑  作者: Mango
let age = 16; // number
let name = "John"; // string
let name = {first:"Jane", last:"Duo"}; // object
let truth = false; // boolean
let sheets = ["HTML","CSS","JS"]; // array
let a; typeof a; // undefined
let a = null; // null