FindElementIndex

package com.company;

import java.util.Random;
import java.util.Scanner;

public class FindElementIndex
{
  public static void main(String[] args)
  {
    Scanner scanner = new Scanner(System.in);
    System.out.println("Vyvedi chislo");
    int inputNum = scanner.nextInt();
    int[] arr = {5, 7, 3};

    while (true) {
      int printed = -1;
      for (int i = 0; i < arr.length; i++) {
        if (arr[i] == inputNum) {
          printed = i;
          break;
        }
      }
      System.out.println(printed);
      System.out.println("Vyvedi chislo");
      inputNum = scanner.nextInt();
    }
  }
}