Thread: User entry needs to be exactly 5 digits

Originally Posted by tyneframe

Just starting out in Java and need a little help.
I'm writing a simple code where the user is asked to enter a 5 digit number, otherwise they get a 'please try again' message. I've figured out most of it, except the number 00000 (with five zeros) must also be an acceptable entry, but not acceptable if they were to enter just one zero. Here's what my if statement looks like so far:

if(userEntry < 100000 && userEntry > 9999){
        System.out.println("Your chosen number is: "+userEntry);
}else{
	System.out.println("Your entry is invalid. Please try again.");
	main(args);
	}

How do I write the code to make 00000 an acceptable entry, but not 0?

You could read it in as a String and check that the String length == 5. Then parse it into an int and make sure it parses OK by doing it inside of a try/catch block.

As an aside, you're repeating your main method by using recursion -- by having the main method call itself, and I'm not sure that I'd do things this way. Why not instead use a simple while loop?

Repeating the main method seemed like the simplest thing to re-run the code and allow the user to re-enter a number, if their first try was invalid. I am new to this...only a couple of weeks into the course and don't really know anything about loops yet.

I'll gladly give it a try. Do you know where I could find a tutorial or explanation of the code?

And thank you for the quick help.

Originally Posted by tyneframe

Repeating the main method seemed like the simplest thing to re-run the code and allow the user to re-enter a number, if their first try was invalid. I am new to this...only a couple of weeks into the course and don't really know anything about loops yet.

I'll gladly give it a try. Do you know where I could find a tutorial or explanation of the code?

And thank you for the quick help.

You're welcome.

As for a tutorial, the best are to be found here:

• The Java™ Tutorials, The Java™ Tutorials: this holds all the tutorials
• Learning the Java Language: the start of the Java basics section
• The while loops: How to use a while loop

Thank you very much for the help and links. I'll check them out.