line of exit program code?

Ya. as the subject says, i would like to know of a line of code i could use that would exit the program.
the purpose of this is to use it in a for-loop.
thanks for any help you can give

You can exit from the for-loop using a break statement. Read break.

Check out System#exit()

thanks for the responses
sorry John but thats leaving the for-loop process.
i am looking for a line of code used to exit the actual program.

Yes - you are right. I would prefer a normal program execution but not sure of your requirements.

Actually maybe it would be better to find a line of code that will start the program again.
im sort of just messing with loops to get better. i am making a game that sort of resembles zork.
of course it will be much much shorter.

If you want to just leave out a iteration in a for loop, you can use continue. You have to tell the details and post some code to help you better.

I have no idea about the story and am making it up as i go. so i dont think any comments are needed about that.
So when i run this no matter what i type in it results in the first section of the if statement.
The reason for the exit or restart code is so if the character dies it will print you died and will restart or end.

WARNING some text is gory!

import java.util.*; import java.io.*; public class sim { public static void main(String args[]) { System.out.println("your on a journey, you see a troll running " + " at you but there is a sword\nlying behind it. what will you do?"); System.out.println("1. run away\n2. punch it\n3." + " Run around it to the sword\n4. dive between its legs for the sword"); Scanner KbReader = new Scanner(System.in); String ch = KbReader.nextLine(); if(ch != "4") { System.out.print("you died"); } else { System.out.println("your slid under its legs as" + " it swiped for your head. You reached the\nsword," + " it shimmered in the light as the trolls blood dripped down the handle."); } } }

I would advise you to let the for loop terminate by reaching its end. If you count it correctly, it will terminate when it finishes its count. I suggest you don’t try to terminate the JVM. When you reach the last line of the main method, and that completes, program control will return to the JVM which will turn off cleanly. System.exit() is a bit vicious. You won’t notice any problems at this stage, but if you ever use it in a multi‑threaded program, it might terminate a thread which hasn’t finished its task, and you can get corrupted files, etc., if there is a task unfinished.

So when i run this no matter what i type in it results in the first section of the if statement.

The reason is because you use != for String non-equality. You should use the equals() method in the String class.

ok campbell. but do you have any suggestions on how to get the program to the end of the program?

What is the equals() syntax? how do i include it?

Bryce Wade wrote: . . . WARNING some text is gory! . . .

You are right. Those very long lines, which make the code difficult to read. That can be sorted out by closing the Strings with quotes " and using the + operator. You can see how it is done now I have changed it.
That use of \n which you see in so many books, but is mistaken. You are using the wrong line end for Windows®. You ought to use printf and the %n tag.
That use of the == operator or != on reference types, which usually gives you the wrong answer. You should use the equals method or this to compare those Strings.

if (foo.equals(bar)) { // ... } else { // ... }if (!foo.equals(bar)) { // ... } else { // ... }You will see that the version without the ! is much easier to read and understand, so you should use versions without ! as far as possible

If you are using a Scanner, you can use its nextInt() method, then you get 1 2 3 or 4 as ints, and == does work on ints.

so is %n equal to \n ?
and thanks for all of them posts

As far as I know %n only works with System.out.printf (and String.format), not with System.out.println.

and what is the difference between the two print statements?

It uses \r\n on Windows® or \r on old Macs (probably not many of those around still) instead of \n which is correct on Linux. A lot of applications can compensate for wrong line ends, but some, eg Microsoft NotePad®, can’t.

Jesper de Jong wrote:As far as I know %n only works with System.out.printf (and String.format), not with System.out.println.

I said printf.

Bryce Wade wrote:and what is the difference between the two print statements?

What do their docs say?

Bryce Wade wrote:ok campbell. but do you have any suggestions on how to get the program to the end of the program?

I think you've already been told more than once: System.exit(int) - however, it's usually not needed in normal use.
How about something like this (in my bad pseudo-code):public static void main(String args[]) { play the game; ask the user if they want to play again; while(user's answer is "yes") { play the game; ask the user if they want to play again; } }HIH

Winston

Winston Gutkowski wrote:
I think you've already been told more than once: System.exit(int) - however, it's usually not needed in normal use.

Well, it is if you want to return a non-zero return code from your program.

Ivan Jozsef Balazs wrote:Well, it is if you want to return a non-zero return code from your program.

Hmmm. I prefer Exceptions myself, unless the return code is used simply as a form of IPC.

Winston

There are very few things nowadays which actually use the exit value.

Bryce Wade wrote:thanks for the responses
sorry John but thats leaving the for-loop process.
i am looking for a line of code used to exit the actual program.

Why don't you create a unchecked exception in a if statement, in the for loop on the line where you want to exit from the actual program.
I am a newbie so please suggest me if i am posting something wrong.

Campbell Ritchie wrote:There are very few things nowadays which actually use the exit value.

Every time I write a Java batch program, that is, one to be run from a script, I make sure the program exits with a useful return code.

Ivan Jozsef Balazs wrote:Every time I write a Java batch program, that is, one to be run from a script, I make sure the program exits with a useful return code.

¿Qué,...java batch? ¿Oxymoron, no?

I jest, of course; but the idea of running programs from scripts that can actually do something about a return code other than 0 (except to log it) seems a bit old-fashioned (and I'm an old Sysadmin, so I love scripts).

But please let me know if I'm wrong. It wouldn't be the first time.

Winston

Winston Gutkowski wrote:
but the idea of running programs from scripts that can actually do something about a return code other than 0 (except to log it) seems a bit old-fashioned

The script can make a decision depending on the return code of the Java program for example whether to continue or not the procedure.
With a potent scripting language (like bash), it is no problem to cruft together a script implementing some non-trivial piece of logic,
and a Java program can be a welcome component.

Ivan Jozsef Balazs wrote:With a potent scripting language (like bash), it is no problem to cruft together a script implementing some non-trivial piece of logic...

As I say, I'm an old Unix Sysadmin, so I love bash; but I'd be leery of any system containing complex logic that doesn't have the backing of a proper language (believe me, I've spent half my admin life documenting the scripts I've written).

Power != Efficacy

Winston

There might be a gap between "non-trivial" and complex.

A return-code is useful (beyond being logged) even in a non-trivial (albeit not complex) script.

Cheers!

Ivan Jozsef Balazs wrote:

Winston Gutkowski wrote:
but the idea of running programs from scripts that can actually do something about a return code other than 0 (except to log it) seems a bit old-fashioned

The script can make a decision depending on the return code of the Java program for example whether to continue or not the procedure.
With a potent scripting language (like bash), it is no problem to cruft together a script implementing some non-trivial piece of logic,
and a Java program can be a welcome component.

I honestly can't remember the last time I wrote a shell script that cared about anything other than zero vs. non-zero. And I'm pretty sure that if the JVM dies due to an uncaught exception percolating out of main(), the result code will be non-zero, so I can't say I've ever come across a case where specific System.exit(N) values would be useful. Not saying there can't be such a case, just that, from the script's perspective, "JVM died due to NPE" vs. "JVM died due to missing input file" doesn't seem particularly useful.

Jeff Verdegan wrote:
I honestly can't remember the last time I wrote a shell script that cared about anything other than zero vs. non-zero.

This does not contradict my humble opinion.

A Java program can deliberately (that is, if the JVM did not crash) return a non-zero code if it was not able to perform the task it was supposed to.
The distinction zero-non-zero is also a useful one.
The possibility to set the return code of a Java program is a Good Thing.

For example grep (known to be a highly useful utility also in scripts) returns 0 if the stuff is found, 1 otherwise but 2 on error (file not found etc.)

Lest we should want to write a grep clone in Java (jrep)...

http://www.opendap.org/api/javaDocs/gnu/regexp/util/Grep.html