let arr = ["a","b","c"]在某些隱含轉(zhuǎn)換的應用場景或調(diào)用arr.toString()方法，arr會默認轉(zhuǎn)換成字符串a(chǎn),b,c如何轉(zhuǎn)化成字符串 ["a","b","c"] ，除了自己寫處理邏輯function toNormalString(){  let str;  return str = '[' + this.join(",")+']'}Array.prototype.toNormalString = toNormalStringarr.toNormalString()除此之外，原生的數(shù)組有沒有支持類似的方法？上面這種寫法也有缺點，轉(zhuǎn)化出來的字符串是"[a,b,c]" 而不是 ["a","b","c"]