[Q#25833876][A#25834021] how to prevent duplicates string in array and

First request I don't know how to:

Answer

Maybe you can do it like this: }

APIzation

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class test {
public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    int studentNumbers = input.nextInt();
    input.nextLine();
    List<String> names = new ArrayList<String>();
    int[] volume = new int[100];
    // clear all data to make it clean
    names.clear();
    while (true) {

        if (studentNumbers == 0)
            break;
        else
            for (int i = 0; i < studentNumbers; i++) {
                String studentName = input.next();
                // here is how prevent string duplicates in names[] array like
                if (names.contains(studentName)) {
                    continue;
                }
                if (studentName.length() > 10) {
                    break;
                }
                names.add(studentName);
                int length = input.nextInt();
                int width = input.nextInt();
                int height = input.nextInt();

                System.out.printf("\n%s %d %d %d\n", names.get(i), length, width, height);
                volume[i] = length * height * width;
            }
        int minimum = 0, maximum = 0;
        for (int i = 1; i < studentNumbers; ++i) {
            if (volume[i] < volume[minimum])
                minimum = i;
            if (volume[i] > volume[maximum])
                maximum = i;
        }
        if (volume[minimum] == volume[maximum])
            System.out.println("\nno child lost his jelly\n");
        else
            System.out.printf("\n%s has lost jelly to %s.\n", names.get(minimum), names.get(maximum));
        studentNumbers = input.nextInt();
        input.nextLine();

    }

}

package com.stackoverflow.api;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class Human25834021 {

  public static void preventDuplicateStrings() {
    Scanner input = new Scanner(System.in);
    int studentNumbers = input.nextInt();
    input.nextLine();
    List<String> names = new ArrayList<>();
    int[] volume = new int[100];
    // clear all data to make it clean
    names.clear();
    while (true) {
      if (studentNumbers == 0) {
        break;
      } else {
        for (int i = 0; i < studentNumbers; i++) {
          String studentName = input.next();
          // here is how prevent string duplicates in names[] array like
          if (names.contains(studentName)) {
            continue;
          }
          if (studentName.length() > 10) {
            break;
          }
          names.add(studentName);
          int length = input.nextInt();
          int width = input.nextInt();
          int height = input.nextInt();

          System.out.printf(
            "\n%s %d %d %d\n",
            names.get(i),
            length,
            width,
            height
          );
          volume[i] = length * height * width;
        }
      }
      int minimum = 0, maximum = 0;
      for (int i = 1; i < studentNumbers; ++i) {
        if (volume[i] < volume[minimum]) {
          minimum = i;
        }
        if (volume[i] > volume[maximum]) {
          maximum = i;
        }
      }
      if (volume[minimum] == volume[maximum]) {
        System.out.println("\nno child lost his jelly\n");
      } else {
        System.out.printf(
          "\n%s has lost jelly to %s.\n",
          names.get(minimum),
          names.get(maximum)
        );
      }
      studentNumbers = input.nextInt();
      input.nextLine();
    }
  }
}

package com.stackoverflow.api;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

/**
 * how to prevent duplicates string in array and
 *
 * @author APIzator
 * @see <a href="https://stackoverflow.com/a/25834021">https://stackoverflow.com/a/25834021</a>
 */
public class APIzator25834021 {

  public static void duplicateString() {
    Scanner input = new Scanner(System.in);
    int studentNumbers = input.nextInt();
    input.nextLine();
    List<String> names = new ArrayList<String>();
    int[] volume = new int[100];
    // clear all data to make it clean
    names.clear();
    while (true) {
      if (studentNumbers == 0) break; else for (
        int i = 0;
        i < studentNumbers;
        i++
      ) {
        String studentName = input.next();
        // here is how prevent string duplicates in names[] array like
        if (names.contains(studentName)) {
          continue;
        }
        if (studentName.length() > 10) {
          break;
        }
        names.add(studentName);
        int length = input.nextInt();
        int width = input.nextInt();
        int height = input.nextInt();
        System.out.printf(
          "\n%s %d %d %d\n",
          names.get(i),
          length,
          width,
          height
        );
        volume[i] = length * height * width;
      }
      int minimum = 0, maximum = 0;
      for (int i = 1; i < studentNumbers; ++i) {
        if (volume[i] < volume[minimum]) minimum = i;
        if (volume[i] > volume[maximum]) maximum = i;
      }
      if (volume[minimum] == volume[maximum]) System.out.println(
        "\nno child lost his jelly\n"
      ); else System.out.printf(
        "\n%s has lost jelly to %s.\n",
        names.get(minimum),
        names.get(maximum)
      );
      studentNumbers = input.nextInt();
      input.nextLine();
    }
  }
}