Longest Common Prefix

public class Solution {
    public String longestCommonPrefix(String[] strs) {
        if (strs.length==0||strs[0].length()==0){
            return "";
        }
        int n=0;
        String s="";
        char cur=strs[0].charAt(0);
        boolean isreturn=false;
        int index=0;
        while(true){
            for(int i=0;i<strs.length;i++){
                if(index>strs[i].length()-1||strs[i].charAt(index)!=cur){
                    isreturn=true;
                    break;
                }
            }
            if(isreturn){
                return s;
            }else{
               index=index+1;
               s=s+cur;
               if(index>strs[0].length()-1){
                   return s;
               }
               else{
                   cur=strs[0].charAt(index);
               }
            }
        }
    }
}