array problem

[JosAH]

Ok, i see what does the nextLine() do in exact, but can u plz explain more in this lines becuase i didnt quite understand them well

Imagine that your input contains the following characters (as a matter of fact it does):

4<enter>
5: 2 3 12 16 44<enter>
3: 2 6 7<enter>
6: 1 2 3 8 9 99<enter>
2: 89 99<enter>

To be able to read it all you have to call nextInt() (to read the first int), nextLine() (to get rid of that <enter> character), nextInt() (to read the first integer on the next line), skip(":") (to get rid of that colon, nextInt(), nextInt() ... a few times and readLine() again, etc. etc.

kind regards,

Jos

[aizen92]

ok so i think i got 2 versions of what might be a correction of the previous code with the correction u told me about

version 1:

import java.util.Scanner;
import java.io.*;
import java.util.Arrays;

public class Problem3
{
    public static void main (String[] args) throws FileNotFoundException
    {
        Scanner input = new Scanner(new File(args[0]));
        int N = input.nextInt();
        [B]input.nextLine();[/B]
        int [][] array = new int [N][];
        
        while(input.hasNextLine())
        {
            String str = input.nextLine();
            Scanner scanLine = new Scanner (str);
            
            int i = 0;
            while(scanLine.hasNextInt())
            {
                int n = input.nextInt();
                scanLine.skip(":");
                
                [B]for ( int j = 0; j < n; j++)
                {
                    array [i][j] = scanLine.nextInt();
                }
                
                scanLine.nextLine();[/B]
                i++;
            }
        }
        System.out.println(Arrays.toString(array));
    }
}

version 2:

import java.util.Scanner;
import java.io.*;
import java.util.Arrays;

public class Problem3
{
    public static void main (String[] args) throws FileNotFoundException
    {
        Scanner input = new Scanner(new File(args[0]));
        int N = input.nextInt();
        [B]input.nextLine();[/B]
        int [][] array = new int [N][];
        
        while(input.hasNextLine())
        {
            String str = input.nextLine();
            Scanner scanLine = new Scanner (str);
            
            int i = 0;
            while(scanLine.hasNextInt())
            {
                int n = input.nextInt();
                scanLine.skip(":");
                [B]array [i][n] = scanLine.nextInt();
                scanLine.nextLine();[/B]
                i++;
            }
        }
        System.out.println(Arrays.toString(array));
    }
}

but when i tried to run it, it still gave me the same result which is the nulls
i hope i did the corrections right

EDIT:

I set a breakpoint on the last while loop in my code to use the debugger, but the thing is i dont think the code reaches this while loop because it gave me the output directly without going through the loop

[Fubarable]

One suggestion to help make your code readable -- don't use [quot&#101;]/[/quot&#101;] tags but instead use [cod&#101;]/[/cod&#101;] tags.

[JosAH]

I set a breakpoint on the last while loop in my code to use the debugger, but the thing is i dont think the code reaches this while loop because it gave me the output directly without going through the loop

Don't use a debugger, use System.out.println( ... ) and print everything you're interested in and everything you think the program must've read.

kind regards,

Jos

[aizen92]

ok so this is my new code

import java.util.Scanner;
import java.io.*;
import java.util.Arrays;

public class Problem3incomplete
{
    public static void main (String[] args) throws FileNotFoundException
    {
        Scanner input = new Scanner(new File(args[0]));
        int N = input.nextInt();
        input.nextLine();
        int [][] array = new int [N][];
        
        while(input.hasNextLine())
        {
            String str = input.nextLine();
            Scanner scanLine = new Scanner (str);

            scanLine.useDelimiter(": ");
            int n = scanLine.nextInt();
            scanLine.useDelimiter(" ");
            
            int i = 0;
            while(scanLine.hasNext())
            {
                [B]for ( int j = 0; j < n; j++)
                {
                    array [i][j] = scanLine.nextInt();
                }[/B]                
                scanLine.nextLine();
                i++;
            }
        }
        System.out.println(Arrays.toString(array));
    }
}

however it gives me an error in the line of the array iside the for loop (bolded one)
the error is mismatchinput thing

the exact error im getting in the console is :

java.util.InputMismatchException
at java.util.Scanner.throwFor(Scanner.java:840)
at java.util.Scanner.next(Scanner.java:1461)
at java.util.Scanner.nextInt(Scanner.java:2091)
at java.util.Scanner.nextInt(Scanner.java:2050)
at Problem3incomplete.main(Problem3incomplete.java:28 )

[JosAH]

however it gives me an error in the line of the array iside the for loop (bolded one) the error is mismatchinput thing

Where are the System.out.println( ... ) calls? Print out the value of the loop variable j, also print out what the String line is you're trying to scan. Don't just guess and don't immediately post here when your program doesn't do what you want it to do. Experiment with the code.

kind regards,

Jos

[aizen92]

ok
i played with thecode a little and it turned great and worked finally
Thanks JosAH for the help