SOURCE

'use strict';
//strict模式，强制通过var申明变量

//数据类型和变量
let a = 1.2;
let b = 1.2345e3;
console.log(b);
let c = NaN;
console.log(c);
let d = Infinity;
console.log(d);

var aa = Math.abs(1/3-(1-2/3)) < 0.0000001;
console.log(aa);

var person= {
    name: 'Bob',
    age: 20,
    tags: ['js','web','mobile'],
    city: 'Hubei',
    hasCar: true,
    zipCode: null
};
console.log(person.name);
console.log(person.zipCode);

var x = 10;
console.log(x = x + 2);