Checking numerical data!! (java)

Fredstar · 03-17-2006, 02:24 AM

Checking numerical data!!

I have to use JOptionPane for a project for school.

I need a quick way to check if the input stream is holding an integer before I parse the data into an integer variable.

I thought I could do this with an if statement but I was wrong, or so I think

Any pointers would help!!

thanks

spooon · 03-17-2006, 06:49 AM

so you need to parse a string? you could maybe do something like this:

Code:

int foo; String bar;
try {
  foo = Integer.parseInt(bar);
} catch (NumberFormatException e) {
  // not an integer
}

xhi · 03-17-2006, 07:42 AM

i usually use String::matches(String) .. it takes a regular expression as a string.. if you put it in your action handler then you can sort through input before you need an exception handled..

here is an example with a text box..
ex

Code:

if(textArea.getText().matches("[0-9]+"))
    System.out.println("good input");
else System.out.println("BAD input");