该题意思是判断一个字符串，如果全部是大写或全部是小写再或者只有首字母是大写则返回true，其余返回false；

 

 

1 /** 2  * @param {string} word 3  * @return {boolean} 4  */ 5 var detectCapitalUse = function(word) { 6     var thisWord = word; 7     var length = thisWord.length; 8     var thisWordUpper = thisWord.toUpperCase(); 9     var thisWordLower = thisWord.toLowerCase();10     var thisWordFirst = thisWord.substr(0, 1);11     var thisWordOther = thisWord.substr(1,length-1);12     if((thisWord ==thisWordUpper)||(thisWord == thisWordLower)){13         return true;14     }else if((thisWordFirst == thisWordFirst.toUpperCase())&&(thisWordOther == thisWordOther.toLowerCase())){15         return true;16     }else{17         return false;18     }19 };