1.JSON.stringify()：js对象->json
<script>
//Number
console.log(JSON.stringify(3.14));
//字符串
console.log(JSON.stringify('php.cn'));
//布尔型
console.log(JSON.stringify(true));
console.log(JSON.stringify(null));
//对象
console.log(JSON.stringify({x:'a',y:'b'}));
//数组
console.log(JSON.stringify([1,2,3]));
</script>2.JSON.parse(): json->js对象
<script>
console.log(JSON.parse(
`{
"a":1,
"b":2,
"c":3
}`
));
console.log(typeof JSON.parse(
`{
"a":1,
"b":2,
"c":3
}`));
let jsObj=JSON.parse(`{"a":1,"b":2,"c":3}`);
//判断是否为Object
console.log(jsObj instanceof Object);
console.log(typeof jsObj);
//promise fetch
</script> 推荐：《2021年js面试题及答案（大汇总）》
