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Java

What is the syntax for Java to use a if - then goto command?

I used to be able to use IF F$ = something then goto something

something: commands

In qbasic. Is there a goto for java or is it all in separate classes?

Do you know what methods are? Unlike BASIC, where you do GOTO LINENUMBER, Java doesn't use line numbers. So you need to write methods for a separate "process". Read on methods if you don't know what they are, and you will like it a little more than the GOTO stuff in BASIC

you just need to work with if- / if-else statements.....
like:

if( i == 0)
{
g.drawString ("The number is 0", 100, 50);
}

////

else
{
g.drawString ("The number isn't 0", 100, 50);
}

LoL yeah I know it isn't state of the art example, but don't know exactly what you need... Not quite familair with BASIC or any other compiled language
Looks a lot like C++ thay say...... Well the only thing I know is that the standard things like if/else/etc look a lot like the ones used in php

Would:

public int mult2(int p, int q){
int n;
n=(p*q)+2;
return n;
}

be an example of a method?

One last question:

How do I get a text input from a user and use it as a variable? I tried

Code:

KeyboardReader reader = new KeyboardReader();
String choice;
System.out.print("Enter your name");
choice = Keyboard.readString();

But it didn't work.

the method you had is right! what you would have to do is have something like:

int temp = 0, p = 1, q = 7;

temp = mult2(p, q)

and it would save what is n in the method in temp, you can also have methods that don't return anything, just replace the int by void!

and to read from keyboard you use:

var1 = keyboard.readLine();

to save it as int you use:

Integer.parseInt(keyboard.readLine());

because java takes all input as a String, and that would convert to integer

double.parseDouble(keyboard.readLine());

converts to double!

Have FUn!

Let me give you something that will eiminate redundant statements for user input. Try the following method:

Code:

private static String readInput(){
try{
BufferedReader keyboard = new BufferedReader(
new InputStreamReader(System.in));
return keyboard.readLine();
}
catch (IOException e){}
return "";
}

Now, whenever you need user input, simply do:
String s = readInput;

And what The One said will apply to this as well

PS: Just realised the difference in syntax for the "reader". Don't worry about it. I doubt if there's much of a difference.

Last edited by kgx, January 17th, 2003 09:44 AM (Edited 1 times)

Ok, I got the get user input figured out, but now I have another problem. When I get the text input from a user, I want it to send them to a different class and execute the commands there.

Code:

System.out.print("? ");
String subject = reader.readLine("");
if (subject == "Algebra")
System.out.println("Insert class");
else if (subject == choiceGeometry)
System.out.println("Insert class");
else if (subject == choicePhysics)
System.out.println("insert class");
else if (subject == choiceTrig)
System.out.println("insert class");

But nothing seems to happen after I type in what "subject" should be.

Zwitterion I removed the double post you had, which is probably why TheOne gave the response s/he did.

TheOne I also removed the response to the post that I removed of Zwitterion's. In case you were wondering where it went.

heh, that's kind of confusing.

Last edited by akuma, January 18th, 2003 12:41 AM (Edited 1 times)

that's because you cannot compare Strings in java using ==
you have to invoke the .equals method.

Code:

if ( subject.equals("choiceTrig"))
// would be true if the user input "choiceTrig"
// and then this fuction would call whatever
// you needed