Calculator.java

import java.util.Scanner;

public class Calculator{

  public static void cout(String text){
    System.out.print(text);
  }

  public static int menu(){
    Scanner get = new Scanner(System.in);
    System.out.println("What would you like to do?\n1. Add\n2. Subtract\n3. Multiply\n4. Divide\n5. Exit");
    System.out.print("> ");
    int option = get.nextInt();
    return option;
  }

  public static void input(){
    System.out.print("Enter number : ");
  }

  public static float basic(int opt, float x, float y){
    cout("Basic module.\n");
    switch(opt){
      case 1:
        return (x + y);
      case 2:
        return (x - y);
      default:
        System.out.println("You're honestly a moron.");
        return 0;
    }
  }

  public static float complex(int opt, float x, float y){
    cout("Complex module.\n");
    switch (opt) {
      case 3:
        return (x * y);
      case 4:
        return (x / y);
      default:
        System.out.println("You're honestly a moron.");
        return 0;
    }
  }

  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    float result, x ,y;
    int option = menu();
    if (option >= 0 && option <= 4) {
      input();
      x = sc.nextFloat();
      input();
      y = sc.nextFloat();
      if (option <= 2 && option >= 0) {
        result = basic(option, x, y);
        System.out.println("Answer : " + result);
      }
      else if (option > 2 && option <= 4){
        result = complex(option, x, y);
        System.out.println("Answer : " + result);
      }
    }
    else{
      System.out.println("Exit.");
    }
  }
}