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I am trying to make a application and for one part of the application I need to get a input from the user stating how many times there click their mouse in 1 second. I want the input their give to be between 1-10 and any other number given e.g. 0, -1, 11 to provide them with a error and ask them to input a valid number of 1-10. Also if the user types in any character e.g. name, A, Jo or hello, to also provide them with a error and ask them to provide the correct input. Below is what I have but it does not work.

    int OrginalMouseClick;

    String Mouseclick = JOptionPane.showInputDialog("Write down how many times you can click your mouse button in 1 second");
    int Mouseclick2 = Integer.parseInt(Mouseclick);

    while (Mouseclick2 < 1 || Mouseclick2 > 10) {
        String Mouseclick = JOptionPane.showInputDialog("Write down how many times you can click your mouse button in 1 second");   
         if (Mouseclick2 >= 1 || Mouseclick2 <10) {
             OrginalMouseClick = Mouseclick2;
             }
         }

I haven't yet implemented not to accept any characters like name, j, A, hello because I am not sure how I can do this, can someone show me please.

edit: int mouseClick;

    do {
        while (!str.hasNextInt()) {
            String str = JOptionPane.showInputDialog("Write down how many times you can click your mouse button in 1 second");
            str.next(); // this is important!
        }
        String str = JOptionPane.showInputDialog("Write down how many times you can click your mouse button in 1 second");
        mouseclick = Integer.parseInt(str);
    }
    while (mouseclick < 1 || mouseclick > 10);
  • Use a do-while loop instead of a while loop and you can void the repeated code. Additionally you don't parse the newly entered string into an integer... – Tim B Jan 19 '14 at 11:10
  • Can you give me a example, please. –  Jan 19 '14 at 11:13

2 Answers2

1

An example as requested:

int mouseClick;

do {
    String str = JOptionPane.showInputDialog("Write down how many times you can click your mouse button in 1 second");
    mouseclick = Integer.parseInt(str);
}
while (mouseclick < 1 || mouseclick > 10);
Tim B
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  • Hi Tim, it works, thanks you so much, how would I prevent the user from entering any characters e.g. instead of a number if there type in a letter or letters I want the program to ask to them again to write the number of mouse clicks. –  Jan 19 '14 at 11:22
  • Integer.parseInt will throw an exception. Just catch the exception and in the catch set mouseClick to -1. The loop will then repeat. – Tim B Jan 19 '14 at 11:23
  • Can you please show me an example. I am new to java and learning as I go along. –  Jan 19 '14 at 11:31
  • @user3211917 Google "java exceptions". I'm not writing your whole program for you and I've told you all you need to know to work it out. – Tim B Jan 19 '14 at 12:16
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Use do while loop instead of while loop. This lets you run the loop atleast once before it tests the condition, where you can test the input.

String input = null;
do {
    //get the input from user
} while (isInputValid); //check input validity here

Example:

 Scanner input= new Scanner(System.in);
 do {
    System.out.println("Please enter the advertising cost: ");
    advertCost = input.nextDouble();

    } while (advertCost >= 100000 || advertCost <= 900000);

I have added link on how to validate inputs

Hope this helps!

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Keerthivasan
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