Try/Catch exception help in Java












1















The program I am making has a console-based text menu to select an option between 1 and 2, I need it to catch for any input that isnt a number, and isnt a number between 1 and 2. This is what I have



    Scanner scan = new Scanner(System.in);
int number = 0;
try {
System.out.println("Enter a number ");
System.out.println("1.");
System.out.println("2.");
number = scan.nextInt();
}
catch (ArithmeticException e) {
System.out.println("Arithmetic Exception");
}
catch (Exception e) {
if (!(number == 1) || !(number == 2)) {
System.out.println("Exception");
}
}


Any insight on where I have gone wrong is appreciated!










share|improve this question


















  • 2





    You say you’ve gone wrong - where does the actual behaviour differ from the intended?

    – MTCoster
    Nov 14 '18 at 20:00






  • 1





    What's the problem? You didn't specify.

    – NiVeR
    Nov 14 '18 at 20:01






  • 2





    Putting in the number 3, for example, isn't a system exception but a program-defined boundary. Use an if-statement for that inside the try-block.

    – Drew Kennedy
    Nov 14 '18 at 20:01








  • 2





    You don't get an ArithmeticException from reading an int from a Scanner, as you are not doing any arithmetic. And a number is always either not equal to 1 or not equal to 2.

    – Andy Turner
    Nov 14 '18 at 20:02













  • It won't throw an exception for you, you need to do the logic and throw the exception.

    – SPlatten
    Nov 14 '18 at 20:03
















1















The program I am making has a console-based text menu to select an option between 1 and 2, I need it to catch for any input that isnt a number, and isnt a number between 1 and 2. This is what I have



    Scanner scan = new Scanner(System.in);
int number = 0;
try {
System.out.println("Enter a number ");
System.out.println("1.");
System.out.println("2.");
number = scan.nextInt();
}
catch (ArithmeticException e) {
System.out.println("Arithmetic Exception");
}
catch (Exception e) {
if (!(number == 1) || !(number == 2)) {
System.out.println("Exception");
}
}


Any insight on where I have gone wrong is appreciated!










share|improve this question


















  • 2





    You say you’ve gone wrong - where does the actual behaviour differ from the intended?

    – MTCoster
    Nov 14 '18 at 20:00






  • 1





    What's the problem? You didn't specify.

    – NiVeR
    Nov 14 '18 at 20:01






  • 2





    Putting in the number 3, for example, isn't a system exception but a program-defined boundary. Use an if-statement for that inside the try-block.

    – Drew Kennedy
    Nov 14 '18 at 20:01








  • 2





    You don't get an ArithmeticException from reading an int from a Scanner, as you are not doing any arithmetic. And a number is always either not equal to 1 or not equal to 2.

    – Andy Turner
    Nov 14 '18 at 20:02













  • It won't throw an exception for you, you need to do the logic and throw the exception.

    – SPlatten
    Nov 14 '18 at 20:03














1












1








1








The program I am making has a console-based text menu to select an option between 1 and 2, I need it to catch for any input that isnt a number, and isnt a number between 1 and 2. This is what I have



    Scanner scan = new Scanner(System.in);
int number = 0;
try {
System.out.println("Enter a number ");
System.out.println("1.");
System.out.println("2.");
number = scan.nextInt();
}
catch (ArithmeticException e) {
System.out.println("Arithmetic Exception");
}
catch (Exception e) {
if (!(number == 1) || !(number == 2)) {
System.out.println("Exception");
}
}


Any insight on where I have gone wrong is appreciated!










share|improve this question














The program I am making has a console-based text menu to select an option between 1 and 2, I need it to catch for any input that isnt a number, and isnt a number between 1 and 2. This is what I have



    Scanner scan = new Scanner(System.in);
int number = 0;
try {
System.out.println("Enter a number ");
System.out.println("1.");
System.out.println("2.");
number = scan.nextInt();
}
catch (ArithmeticException e) {
System.out.println("Arithmetic Exception");
}
catch (Exception e) {
if (!(number == 1) || !(number == 2)) {
System.out.println("Exception");
}
}


Any insight on where I have gone wrong is appreciated!







java






share|improve this question













share|improve this question











share|improve this question




share|improve this question










asked Nov 14 '18 at 19:59









Paul JonesPaul Jones

266




266








  • 2





    You say you’ve gone wrong - where does the actual behaviour differ from the intended?

    – MTCoster
    Nov 14 '18 at 20:00






  • 1





    What's the problem? You didn't specify.

    – NiVeR
    Nov 14 '18 at 20:01






  • 2





    Putting in the number 3, for example, isn't a system exception but a program-defined boundary. Use an if-statement for that inside the try-block.

    – Drew Kennedy
    Nov 14 '18 at 20:01








  • 2





    You don't get an ArithmeticException from reading an int from a Scanner, as you are not doing any arithmetic. And a number is always either not equal to 1 or not equal to 2.

    – Andy Turner
    Nov 14 '18 at 20:02













  • It won't throw an exception for you, you need to do the logic and throw the exception.

    – SPlatten
    Nov 14 '18 at 20:03














  • 2





    You say you’ve gone wrong - where does the actual behaviour differ from the intended?

    – MTCoster
    Nov 14 '18 at 20:00






  • 1





    What's the problem? You didn't specify.

    – NiVeR
    Nov 14 '18 at 20:01






  • 2





    Putting in the number 3, for example, isn't a system exception but a program-defined boundary. Use an if-statement for that inside the try-block.

    – Drew Kennedy
    Nov 14 '18 at 20:01








  • 2





    You don't get an ArithmeticException from reading an int from a Scanner, as you are not doing any arithmetic. And a number is always either not equal to 1 or not equal to 2.

    – Andy Turner
    Nov 14 '18 at 20:02













  • It won't throw an exception for you, you need to do the logic and throw the exception.

    – SPlatten
    Nov 14 '18 at 20:03








2




2





You say you’ve gone wrong - where does the actual behaviour differ from the intended?

– MTCoster
Nov 14 '18 at 20:00





You say you’ve gone wrong - where does the actual behaviour differ from the intended?

– MTCoster
Nov 14 '18 at 20:00




1




1





What's the problem? You didn't specify.

– NiVeR
Nov 14 '18 at 20:01





What's the problem? You didn't specify.

– NiVeR
Nov 14 '18 at 20:01




2




2





Putting in the number 3, for example, isn't a system exception but a program-defined boundary. Use an if-statement for that inside the try-block.

– Drew Kennedy
Nov 14 '18 at 20:01







Putting in the number 3, for example, isn't a system exception but a program-defined boundary. Use an if-statement for that inside the try-block.

– Drew Kennedy
Nov 14 '18 at 20:01






2




2





You don't get an ArithmeticException from reading an int from a Scanner, as you are not doing any arithmetic. And a number is always either not equal to 1 or not equal to 2.

– Andy Turner
Nov 14 '18 at 20:02







You don't get an ArithmeticException from reading an int from a Scanner, as you are not doing any arithmetic. And a number is always either not equal to 1 or not equal to 2.

– Andy Turner
Nov 14 '18 at 20:02















It won't throw an exception for you, you need to do the logic and throw the exception.

– SPlatten
Nov 14 '18 at 20:03





It won't throw an exception for you, you need to do the logic and throw the exception.

– SPlatten
Nov 14 '18 at 20:03












3 Answers
3






active

oldest

votes


















1














If you want to throw an exception, this is easy but take care with the condition:



Scanner scan = new Scanner(System.in);
int number = 0;
try {
System.out.println("Enter a number ");
System.out.println("1.");
System.out.println("2.");
number = scan.nextInt();
if ((number != 1) && (number != 2)){
throw new Exception();
}
}
catch (InputMismatchException e) {
System.out.println("This is not a number");
}
catch (Exception e) {
System.out.println("Inside here because the number is not 1 or 2");
}


The condition



(number != 1) && (number != 2)


is true if number is not (1 or 2)






share|improve this answer

































    0














        Scanner scan = new Scanner(System.in);
    int number = 0;
    try {
    System.out.println("Enter a number ");
    System.out.println("1.");
    System.out.println("2.");
    number = scan.nextInt();
    if (number != 1 && number != 2){
    throw new Exception();
    }
    }
    catch (ArithmeticException e) {
    System.out.println("Arithmetic Exception");
    }
    catch (Exception e) {
    System.out.println("Inside here because the number is not 1 or 2 ");
    }





    share|improve this answer

































      0














      As a suggestion, you can use



      if ((number != 1) || (number != 2))



      instead of



      if (!(number == 1) || !(number == 2))






      share|improve this answer





















      • 1





        Sure, but why not just use if (true), that's equivalent and simpler again.

        – Andy Turner
        Nov 14 '18 at 20:15











      Your Answer






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      3 Answers
      3






      active

      oldest

      votes








      3 Answers
      3






      active

      oldest

      votes









      active

      oldest

      votes






      active

      oldest

      votes









      1














      If you want to throw an exception, this is easy but take care with the condition:



      Scanner scan = new Scanner(System.in);
      int number = 0;
      try {
      System.out.println("Enter a number ");
      System.out.println("1.");
      System.out.println("2.");
      number = scan.nextInt();
      if ((number != 1) && (number != 2)){
      throw new Exception();
      }
      }
      catch (InputMismatchException e) {
      System.out.println("This is not a number");
      }
      catch (Exception e) {
      System.out.println("Inside here because the number is not 1 or 2");
      }


      The condition



      (number != 1) && (number != 2)


      is true if number is not (1 or 2)






      share|improve this answer






























        1














        If you want to throw an exception, this is easy but take care with the condition:



        Scanner scan = new Scanner(System.in);
        int number = 0;
        try {
        System.out.println("Enter a number ");
        System.out.println("1.");
        System.out.println("2.");
        number = scan.nextInt();
        if ((number != 1) && (number != 2)){
        throw new Exception();
        }
        }
        catch (InputMismatchException e) {
        System.out.println("This is not a number");
        }
        catch (Exception e) {
        System.out.println("Inside here because the number is not 1 or 2");
        }


        The condition



        (number != 1) && (number != 2)


        is true if number is not (1 or 2)






        share|improve this answer




























          1












          1








          1







          If you want to throw an exception, this is easy but take care with the condition:



          Scanner scan = new Scanner(System.in);
          int number = 0;
          try {
          System.out.println("Enter a number ");
          System.out.println("1.");
          System.out.println("2.");
          number = scan.nextInt();
          if ((number != 1) && (number != 2)){
          throw new Exception();
          }
          }
          catch (InputMismatchException e) {
          System.out.println("This is not a number");
          }
          catch (Exception e) {
          System.out.println("Inside here because the number is not 1 or 2");
          }


          The condition



          (number != 1) && (number != 2)


          is true if number is not (1 or 2)






          share|improve this answer















          If you want to throw an exception, this is easy but take care with the condition:



          Scanner scan = new Scanner(System.in);
          int number = 0;
          try {
          System.out.println("Enter a number ");
          System.out.println("1.");
          System.out.println("2.");
          number = scan.nextInt();
          if ((number != 1) && (number != 2)){
          throw new Exception();
          }
          }
          catch (InputMismatchException e) {
          System.out.println("This is not a number");
          }
          catch (Exception e) {
          System.out.println("Inside here because the number is not 1 or 2");
          }


          The condition



          (number != 1) && (number != 2)


          is true if number is not (1 or 2)







          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited Nov 14 '18 at 20:26

























          answered Nov 14 '18 at 20:15









          forpasforpas

          13.6k3624




          13.6k3624

























              0














                  Scanner scan = new Scanner(System.in);
              int number = 0;
              try {
              System.out.println("Enter a number ");
              System.out.println("1.");
              System.out.println("2.");
              number = scan.nextInt();
              if (number != 1 && number != 2){
              throw new Exception();
              }
              }
              catch (ArithmeticException e) {
              System.out.println("Arithmetic Exception");
              }
              catch (Exception e) {
              System.out.println("Inside here because the number is not 1 or 2 ");
              }





              share|improve this answer






























                0














                    Scanner scan = new Scanner(System.in);
                int number = 0;
                try {
                System.out.println("Enter a number ");
                System.out.println("1.");
                System.out.println("2.");
                number = scan.nextInt();
                if (number != 1 && number != 2){
                throw new Exception();
                }
                }
                catch (ArithmeticException e) {
                System.out.println("Arithmetic Exception");
                }
                catch (Exception e) {
                System.out.println("Inside here because the number is not 1 or 2 ");
                }





                share|improve this answer




























                  0












                  0








                  0







                      Scanner scan = new Scanner(System.in);
                  int number = 0;
                  try {
                  System.out.println("Enter a number ");
                  System.out.println("1.");
                  System.out.println("2.");
                  number = scan.nextInt();
                  if (number != 1 && number != 2){
                  throw new Exception();
                  }
                  }
                  catch (ArithmeticException e) {
                  System.out.println("Arithmetic Exception");
                  }
                  catch (Exception e) {
                  System.out.println("Inside here because the number is not 1 or 2 ");
                  }





                  share|improve this answer















                      Scanner scan = new Scanner(System.in);
                  int number = 0;
                  try {
                  System.out.println("Enter a number ");
                  System.out.println("1.");
                  System.out.println("2.");
                  number = scan.nextInt();
                  if (number != 1 && number != 2){
                  throw new Exception();
                  }
                  }
                  catch (ArithmeticException e) {
                  System.out.println("Arithmetic Exception");
                  }
                  catch (Exception e) {
                  System.out.println("Inside here because the number is not 1 or 2 ");
                  }






                  share|improve this answer














                  share|improve this answer



                  share|improve this answer








                  edited Nov 14 '18 at 23:45

























                  answered Nov 14 '18 at 20:11









                  Akeme UAkeme U

                  113




                  113























                      0














                      As a suggestion, you can use



                      if ((number != 1) || (number != 2))



                      instead of



                      if (!(number == 1) || !(number == 2))






                      share|improve this answer





















                      • 1





                        Sure, but why not just use if (true), that's equivalent and simpler again.

                        – Andy Turner
                        Nov 14 '18 at 20:15
















                      0














                      As a suggestion, you can use



                      if ((number != 1) || (number != 2))



                      instead of



                      if (!(number == 1) || !(number == 2))






                      share|improve this answer





















                      • 1





                        Sure, but why not just use if (true), that's equivalent and simpler again.

                        – Andy Turner
                        Nov 14 '18 at 20:15














                      0












                      0








                      0







                      As a suggestion, you can use



                      if ((number != 1) || (number != 2))



                      instead of



                      if (!(number == 1) || !(number == 2))






                      share|improve this answer















                      As a suggestion, you can use



                      if ((number != 1) || (number != 2))



                      instead of



                      if (!(number == 1) || !(number == 2))







                      share|improve this answer














                      share|improve this answer



                      share|improve this answer








                      edited Nov 15 '18 at 5:53









                      Rahul Sharma

                      2,3191819




                      2,3191819










                      answered Nov 14 '18 at 20:09









                      kamilyrbkamilyrb

                      187




                      187








                      • 1





                        Sure, but why not just use if (true), that's equivalent and simpler again.

                        – Andy Turner
                        Nov 14 '18 at 20:15














                      • 1





                        Sure, but why not just use if (true), that's equivalent and simpler again.

                        – Andy Turner
                        Nov 14 '18 at 20:15








                      1




                      1





                      Sure, but why not just use if (true), that's equivalent and simpler again.

                      – Andy Turner
                      Nov 14 '18 at 20:15





                      Sure, but why not just use if (true), that's equivalent and simpler again.

                      – Andy Turner
                      Nov 14 '18 at 20:15


















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