quick question

Laptop2250 · 10-15-2003, 05:13 PM

In java, jdk2.4.1 i am trying to let a user choose options, a small program that is supposed to be a calculator. with 4 options with the output being:

Calculator

1.Addition
2.Subtration

Can somebody tell me how I can allow a user to choose option 1 or 2 and let the computer do the calculation (if use chooses one, how can i let him choose 2 integers to add)

thanks

h/w · 10-15-2003, 08:56 PM

Code:

do {
  print_out_user_options;

  // either set limit to number of variables (like only 2), or store them all in a vector (using some delimter- like 2+2+2+2 ..... with the operation symbols as delimiters)
  read_user_selection; 

  switch (user_selection) {
      case 1: add_vars; break;
      case 2: sub_vars; break;
      default: wtf; break;
   }
} while (not_quit)

so you basically have to just read the options the user enters, and just print out the result of the operation. dont know if i was of any help here ... maybe i shoulda written java code ...

megaspaz · 10-15-2003, 09:56 PM

if this is a console app, you can read input from the console using this:

Code:

InputStreamReader ins = new InputStreamReader (System.in);
BufferedReader input = new BufferedReader (ins);
String strInput = "";
int i, j;

//this will get the input
try
{
	strInput = input.readLine();

	//check for valid operand here

	//to get input for integers using strInput = input.readLine and parsing
	//an integer using Integer.parseInt (strInput);
	try
	{
		//get integers here using Integer.parseInt
	}
	catch (Exception e)
	{
		System.out.println ("ParseInt error. You didn't enter an integer");
	}
}
catch (IOException e)
{
	e.printStackTrace ();
}

from here you can reuse strInput for getting the operation, the first integer, and the second integer. you can use Integer.parseInt (strInput); to try to parse an integer.