ES6开始,js中用let关键字来声明变量,而且js是一门弱类型语言,变量可以存放不同类型的值
<script>
let str = "小帅和小美"
console.log(str);
let i = 1314;
console.log(i);
let d = 521.1314;
console.log(d);
let b = true;
console.log(b)
</script>
2.js中用const关键字来声明常量,常量的值不能别改变
<script>
const pi = 3.14;
console.log(pi);
//修改pi的值,浏览器会报错,运行结果如下图
pi = 4.5;
console.log(pi);
</script>