js如何判断一个对象是否为空对象

方法1

let obj1 = {}
let obj2 = {a:1}

function func(obj)
{
    for(let key in obj)
        return false
    return true
}

console.log(func(obj1))
console.log(func(obj2))

方法2

let obj1 = {}
let obj2 = {a:1}

function func(obj)
{
    if(Object.keys(obj).length === 0)
        return true
    return false
}

console.log(func(obj1))
console.log(func(obj2))

方法3

let obj1 = {}
let obj2 = {a:1}

function func(obj)
{
    if(JSON.stringify(obj) === '{}')
        return true
    return false
}

console.log(func(obj1))
console.log(func(obj2))