摘要：
1.将json对象转化为json字符串，再判断该字符串是否为"{}" var data = {}; var b = (JSON.stringify(data) == "{}"); alert(b);//true 2.for in 循环判断 var obj = {}; var b = function 阅读全文
摘要：
// const add = (x) => x + 5; // const multiplication = (x) => x * 5; // const subtraction = (x) => x - 5; // const division = (x) => x / 5; // const h 阅读全文