Array returns wrong value in java

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Array returns wrong value in java

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#1 by (1 votes)
#2 by (0 votes)

0

I have a question about a college job. I can read with numbers, remove the ";" and pass the values to the array while reading the file. However, when I try to access an array position outside of the file read, it does not return the value I have in the file, but another value. If anyone can help thank you.

ARCHIVE I READ

10
1;1;1
2;2;3;2;150;20
3;3;3;1;100;10
4;4;3;4;350;30
5;5;3;1;100;10
6;6;3;2;150;20
7;7;3;3;100;10
8;8;3;5;500;10
9;9;2
10;10;3;1;100;10

PROGRAM OUTPUT

and so on ...

If I want to read the number 2 that is in the 5th position of the output, I do:

 System.out.println(array[4]);

and instead of returning the number 2 it returns the 100.

MY CODE

package jogo;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;


public class Tabuleiro {

private static BufferedReader br;

public static void main(String[] args) {

        String[] array = null;

        try {
            br = new BufferedReader(new FileReader("/home/overwatch/tabuleiro1.txt"));
            String linha = br.readLine();

            while(linha!=null){
                array = linha.split(";");
                linha = br.readLine();

                for(int i=0; i < array.length;i++){
                    System.out.println(array[i]);
                }
            }   
            br.close();

            //imprimindo o 3 valor que está no array
            System.out.println(array[4]);

        } catch (IOException ioe) {
            ioe.printStackTrace();
        }
    }
}

java string array arquivo for

asked by anonymous 08.06.2017 / 01:17

2 answers

0

You are not storing in the array every line you read. One proposal is to do this:

 public static List<String> leExibeArquivo(String arquivo) {
        String s, temp;            
        //   HashSet<String> valores = new HashSet<>();//ArrayList antes
        List<String> valores = new ArrayList();
        int i = 0;
        System.out.println("O arquivo aberto é: " + arquivo);
        System.out.println("Exibindo arquivo:");
        try (BufferedReader br = new BufferedReader(new FileReader(arquivo))) {
            while ((s = br.readLine()) != null) {
                System.out.println(s);
                valores.add(s);
            }
        } catch (IOException exc) {
            System.out.println("Erro de E/S " + exc);
        }

        return valores;
    }

You would call the method like this:

 List<String> linhas = new ArrayList<String>();
            String arquivo = "/home/overwatch/tabuleiro1.txt";
            linhas = leExibeArquivo(arquivo);//recebe o arquivo em um ArrayList, cada posição uma linha
            //o retorno do método leExibeArquivo(String) é um ArrayList

And then I could convert it to a normal array as follows:

Object vetorLinhas[] = linhas.toArray();    //converte o ArrayList com as linhas para um array.

        System.out.println("Exibe o vetor com as linhas:"); //cada linha em um aposição do vetor - vai ser usado para comparar
        for (int i = 0; i < vetorLinhas.length; i++) {
            System.out.printf("linhas[%d]= %s\n", i+1, vetorLinhas[i]);   //exibe-o na tela
        }

After that you could call any position directly as the example itself already demonstrates (using vetorLinhas[i] )

Do you understand?

Anything is just go in the comments!

08.06.2017 / 02:01

Removing items from a list How to make a change in "Cascade" using oracle

score 1 · Accepted Answer

In this code here:

while(linha!=null){
    array = linha.split(";");

 ...
}

You are overwriting the array at each iteration in the while. In the end your array will only have the values of the last line of the file ( 10; 3; 1; 100; 10 ) where position 4 is actually the value 100. Your code is displaying in the screen all values of each line of the file, but storing in the array only the last line read. You could use an ArrayList to store values like this:

    public class Tabuleiro {

    private static BufferedReader br;

    public static void main(String[] args) {

        ArrayList<String> array = new ArrayList<>();

        try {
            br = new BufferedReader(new FileReader("/home/overwatch/tabuleiro1.txt"));
            String linha = br.readLine();

            while (linha != null) {
                String[] lineValues = linha.split(";");
                linha = br.readLine();

                for (int i = 0; i < lineValues.length; i++) {
                    array.add(lineValues[i]);
                    System.out.println(lineValues[i]);
                }
            }
            br.close();

            // imprimindo o 3 valor que está no array
            System.out.println(array.get(4));

        } catch (IOException ioe) {
            ioe.printStackTrace();
        }
    }
}