Reverse Words in a String

Reverse Words in a String

翻转string里的单词顺序。

Given an input string, reverse the string word by word.

For example,

Given s = "

the sky is blue

",

return "

blue is sky the

".
Solution:

public String reverseWords(String s) {
if(s == null || s.length() <= 1) {
return s;
}
String[] array = s.split(" ");
StringBuilder sb = new StringBuilder();
for (int i = array.length - 1; i >= 0; i--) {
sb.append(array[i]);
sb.append(" ");
}
if(sb.length() > 0) {
sb.deleteCharAt(sb.length() - 1);
}
return sb.toString();
}

思路：

将单词从string分割出来，逆序重组即可。注意StringBuilder是否会为空。

例如 string = ”    “；

StringBuilder 是非同步的， StringBuffer 是同步的，线程共享的Buffer。