1. Splitting and reversing a sentence a word by word

 class Solution {  
 public String reverseWords(String s) {  
 s = s.trim();  

 String[] split = s.split("\\s+");  
 String rever = "";  

 int pointer = split.length - 1;  
 rever = rever + split[pointer];  
 pointer--;  

 while(pointer >= 0){  
 rever = rever + " " + split[pointer];  
 pointer--;  
 }  

 return rever;  

 }//reverseWords method  
 }