java implements the first character detail in the output string that does not repeat

java implements a non-repeating character detail for the first character in the output string

For example: input name output n, input teeter output r, input namename output null

The specific implementation code is as follows:

import java.util.Scanner;

public class Main
{
  public static void main(String[] args)
  {
    Scanner in = new Scanner(System.in);
    String str = in.next();
    for(int i =0 ; i < str.length() ; i++)
    {
      if(str.lastIndexOf(str.char(i)) == i && 
      str.indexOf(str.char(i)) == i)
      {
        System.out.println(str.char(i));
        break;
      }
    }

  }
}

In this implementation code we use three method members of the String class:

String. length() : Gets the length of the string
String. charAt(int index) : Gets the characters that index index
String. lastIndexOf(char c) : Gets the index of the last occurrence of the character c in a string
String.indexOf(char c) : Gets the index of the character c the first time it appears in a string

We could have implemented these methods without using strings. Here is the code I personally implemented using for loops:

import java.util.Scanner;
public class Main
{
  public static void main(String[] args)
  {
    Scanner in = new Scanner(System.in);
    String str = in.next();
    char[] cb = new char[str.length()];
    // Put a character in a string 1 Time deposit cb[]
    for(int i =0 ;i <str.length() ; i++)
    {
      cb[i] = str.charAt(i);
    }
    for(int i = 0 ; i < str.length() ; i++)
    {
      for(int j = 0 ; j < str.length() ; j++)
      {
        if(cb[i] == cb[j] && cb[i] != '0')
        {
          char c = cb[i];
          for(int z = 0 ; z < str.length() ; z++)
          {
            if(cb[z] == c)
              cb[z] = '0';
          }
        }
      }
    }
    for(int i = 0 ; i <str.length() ; i++)
    {
      if(cb[i] != '0')
      {
        System.out.println(cb[i]);
        break;
      }
    }
  }
}

This approach can be implemented, but it is extremely time-consuming and overhead, so it is best not to use loop nesting, which is costly to the system unless you have to.

Thank you for reading, I hope to help you, thank you for your support to this site!