Best way to get input

[michael delta]

hello, I'm using Scanner class to get input from user but I noticed there are some other ways to do that. Could you please tell me the pros and cons of each way with a tiny presentation if possible. Thnx in advance!

[michael delta]

I have another question,I'm not starting a new thread for this.
This is an exercise from past exams:

  import java.io.IOException;
public class TryBlockTest011 {

static int i=0, j =0, r=0;

public static void main(String[] args) {
int[] x = {10, 5, 0};
try { r +=divide(x,0);
x[1] = 0;
r +=divide(x,0);
x[1] = 1;
r +=divide(x,1);
} catch(ArithmeticException e) { i++;

} catch(ArrayIndexOutOfBoundsException e) { i++;
}
i++;
System.out.println("\nPress ENTER to exit");
try { System.in.read();
return;
} catch(IOException e) { i++;
} finally { i++;
System.out.println("" + i+" " +j + " " +r);
}
System.out.println("Good Bye");
}

public static int divide(int[] array, int index) {
try { array[index + 2] = array[index]/array[index + 1];
return array[index + 2];
} catch(ArithmeticException e) { j++;
} catch(ArrayIndexOutOfBoundsException e) { j++;
} finally { j++;
}
j++;
return array[index + 2];
}
}  

a. I'm not really getting the control flow
b. What happens if two or more exceptions happen at the same time in a try block?For example

  
int[]x = {3,2,0};
try{x[3]=x[1]/x[2]}

[Campbell Ritchie]

Welcome to JavaRanch
Unusual name (as mine is): is that your real name?

4 popular ways to get entry from the keyboard

Command-line arguments

javax.swing.JOptionPane.showInputDialog() method

BufferedReader wrapped around a Reader, eg InputStreamReader, wrapped around a Stream, eg System.in

java.util.Scanner.

Since Scanner was introduced in 2004 (Java 5) it has probably become the most popular means of keyboard input.

[Campbell Ritchie]

Please use one thread per question, and you would have been better to start a second thread. Your code is difficult to read because you didn't indent it.
You can't get two simultaneous exceptions in the same thread; the first Exception will stop the try before the second Exception can occur. In your example I would expect the ArrayOutOfBoundsException to prevent the potential ArithmeticException from occurring.

You haven't been told to catch ArrayIndexOutOfBoundsException or ArithmeticException, have you?

[michael delta]

Thnx,nice to be here.
As for the name, I'm Greek

Please use one thread per question, and you would have been better to start a second thread.

I'm sorry, I'll do so.

You haven't been told to catch ArrayIndexOutOfBoundsException or ArithmeticException, have you?

I was looking at the exercise, the double exception was just a what-if-case of mine.
So,if I can't get two simultaneous exceptions in the same thread as long as a statement evaluates from right to left wouldn't I expect the ArithmeticException to occur first?

[Campbell Ritchie]

You will have to try it, but if you go left-to-right I would have thought the array index problem would occur first.

[fred rosenberger]

The assignment operator is right-to-left, and is also pretty low in the precedence chart - which makes sense. You have to evaluate the RHS before you can assign it to the left, and you'd want to do almost everything else before you make that assignment.

So I think you'll get a divide by zero error first...i think. I haven't tried it.

[Campbell Ritchie]

fred rosenberger wrote:So I think you'll get a divide by zero error first...i think. I haven't tried it.

I have, and I am keeping quiet about what happened.