Thread: How to make a program quit?

Originally Posted by copelandtml

How would I go about making a statement that will quit when the user enters quit?
I am asking the user to input some data but want the program to stop when the user inputs quit.

And what part of this are you having trouble with? Getting user input? Doing different things based on something else? Exiting?

Normally I'd tell you to investigate the System.exit() method, but I think something much simpler, like a nice structured if or case statement, would be much more appropriate.

Originally Posted by copelandtml

Not sure if this is just more of a preference or something that should be done but I am wondering if when creating variables should they be initialized to something such as a 0 or " "?

example:
int number = 0;
String name = "";

Thanks!

That depends entirely on the context. Does the variable have a logical default value? Also, note that class variables already do have default values, even if you don't specify one.

if(userInput == quit)

needs to be

if(userInput.equals("quit"))

If you want to keep the loop alive whilst the user enteres values, I suggest a 'while' loop.
Then inside that you can add the 'if' statement.

For example:

boolean on = true
 
while(on){
// prompt for user input
if(userInput.equals("quit")){
on = false;
}
//
}

Originally Posted by JavaPF

if(userInput == quit)
needs to be

if(userInput.equals("quit"))

That's assuming that userInput is a String. It could also be that the user is using ints or something of the like (enter 0 to quit).

OP- What I meant was, do it the other way. Instead of checking for user input to quit, check for everything else and let the quit fall through:

while(userInput != quit){
   if(userInput == optionA){
      //do option A
   }
   else if(userInput == optionB){
      //do option B
   }
}
//when you reach here, the user has chosen to quit