對象是空的嗎？ [重複] - Is object empty? [duplicate]

問題：

This question already has answers here : 這個問題在這裏已經有了答案：

How do I test for an empty JavaScript object? 如何測試空的 JavaScript 對象？ (60 answers) (60 個回答)

Closed 4 years ago . 4年前關閉。

What is the fastest way to check if an object is empty or not?檢查對象是否爲空的最快方法是什麼？

Is there a faster and better way than this:有沒有比這更快更好的方法：

function count_obj(obj){
    var i = 0;
    for(var key in obj){
        ++i;
    }

    return i;
}

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解決方案：

參考一： https://stackoom.com/question/KxDd
參考二： Is object empty? [duplicate]