Given a string, find its first non-repeating character in only One scan

You can store 2 arrays: count of each character and the first occurrence(and fill both of them during the first scan). Then the second scan will be unnecessary.

Use String functions of java then you find the solution in only one for loop The Example is show below

import java.util.Scanner;
public class firstoccurance {
public static void main(String args[]){
char [] a ={'h','h','l','l','o'};
//Scanner sc=new Scanner(System.in);
String s=new String(a);//sc.next();
char c;
int i;
int length=s.length();
for(i=0;i<length;i++)
{
    c=s.charAt(i);
    if(s.indexOf(c)==s.lastIndexOf(c))
    {
        System.out.println("first non repeating char in a string   "+c);
        break;
    }
    else if(i==length-1)
    {
        System.out.println("no single char");
    }
}
}
}