Help with loops...

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January 27th, 2013, 05:46 PM

xRynee

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Join Date: Jan 2013

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Help with loops...

So my main goal is to collect a list of names.. then at my own will check the list of names.. i'm stuck because the way "n" variable is acting doesn't make sense to me.. I'm only printing it to see what's going on with it.. Please help me.

import javax.swing.*;
public class Loopinaloop {

public static void main(String[] args) {

String name[] = new String[2500];
for(int i=0;i<++i;i++){
String start = JOptionPane.showInputDialog("Please select the number that you wish to do you wish to do\n1.Give name\n2.Check the list");
if(start.equals("1")){
String names = JOptionPane.showInputDialog("Good! What is your name?");
name[i] = names;

}
else if(start.equals("2")){
for(int n = 0; n<i; n++){

System.out.println(n);

}
}
}
}

}

January 28th, 2013, 06:23 AM

NormR

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Quote:

the way "n" variable is acting doesn't make sense

Please post the program's output and explain what the problem is.

Please edit you post and wrap the code in code tags and remove the extra spaces.

January 28th, 2013, 10:59 AM

Wetmelon

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Well, you have an infinite loop determined by i, which is incremented by 2 on every iteration (i<++i, and i++). In your inner loop, n is defined at 0 then each iteration increments it by one (n++), with the loop ending at n==i

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January 28th, 2013, 08:49 PM

JonthnC

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You would be best off using a while loop in my opinion. A for loop is really inappropriate for what you're doing. Also, you only need to increment i when the user enters 1 (assuming you're using it to store the amount of names entered).

Try structuring your code like this ----

Code:

public static void main(String[] args) {
    String name[] = new String[2500];
    int i = 0;
    while (true) {
        String start = JOptionPane.showInputDialog("Please select the number that you wish to do you wish to do\n1.Give name\n2.Check the list");
        if(start.equals("1")){
            String names = JOptionPane.showInputDialog("Good! What is your name?");
            name[i] = names;
            i++;
        }
        else if(start.equals("2")){
            for(int n = 0; n<i; n++){
                System.out.println(n);
            }
        }
    }
}

You might want to also check out ArrayLists. You could technically have a buffer overflow if the user enters more than 2500 names. Not solving issues such as this can lead to runtime errors (which are a pain to solve) and are also exploitable by hackers

Last edited by JonthnC : January 29th, 2013 at 12:50 AM.

Help with loops...

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