js里对象的深拷贝
let arr = ['8','7','6']; let arrObj = JSON.parse(JSON.stringify(arr)); arrObj[0] = '9'; console.log(arr); // ['8','7','6'] console.log(arrObj); // ['9','7','6']
js对象的判断为空{}
let obj = {};
JSON.stringify(obj) == "{}"
console.log(JSON.stringify(obj) == "{}"); // true