elements of string array unable to compare with a string

Question

I have a quick simple technical problem: I'm trying to read this file:

S,B,C,D,E,F
0,2,1,inf,inf,inf
inf,0,2,inf,inf,inf
inf,inf,0,4,5,inf
inf,1,inf,0,inf,5
inf,inf,inf,inf,0,1
inf,inf,inf,inf,inf,0

and put each elements in some Array:

BufferedReader br = null;
        FileReader fr = null;
        nodes = new ArrayList<Node>();
        edges = new ArrayList<Edge>();

        try 
        {
            fr = new FileReader(filePath);
            br = new BufferedReader(fr);    
            String firstLine = "";
            String line = "";
            String[] words = null;

            firstLine = br.readLine();
            words = firstLine.split(separtor);

            for (int i=0; i<words.length-1;i++)
            {
                nodes.add(new Node(i, words[i]));
            }

            int node = 0;

            while ((line = br.readLine()) != null)
            {
                words = line.split(separtor);

                for (int i=0; i<words.length-1;i++)
                {
                    if (!words[i].equals("inf") || !words[i].equals("0"))
                    {
                        edges.add(new Edge(nodes.get(node), nodes.get(i), Integer.parseInt(words[i])));
                    }
                }
                node++;
            }
        }
        catch (IOException e)
        {

            e.printStackTrace();

        }

The problems come in this line : if (!words[i].equals("inf") || !words[i].equals("0"))

When the string is not "inf" or "0" then you start adding stuff but when I actually run, it still add "0" and "inf" causing an error:

Exception in thread "main" java.lang.NumberFormatException: For input string: "inf"
    at java.lang.NumberFormatException.forInputString(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source)

I did some tests, but I can't still understand why my condition doesn't work.

Thanks in advance.

This is javascript, but applies: https://stackoverflow.com/a/6115869/1615903 — 1615903, Apr 13 '17 at 06:50

Markus · Accepted Answer · 2017-04-13T07:15:03.973

1

You have to replace that or by and and:

 if (!words[i].equals("inf") && !words[i].equals("0"))

With the or you always will enter the block because words[i] is always unequal to "inf" or "0". Up to that your condition in your loop is wrong. Replace

for (int i=0; i<words.length-1;i++)

by

for (int i=0; i<words.length;i++)

Otherwise you will miss the last element of each line.

EDIT: you also have to change the condition in the other loop from

   for (int i=0; i<words.length-1;i++)
            {
                nodes.add(new Node(i, words[i]));
            }

to

   for (int i=0; i<words.length;i++)
            {
                nodes.add(new Node(i, words[i]));
            }

edited Apr 13 '17 at 07:15

answered Apr 13 '17 at 06:51

Markus

1,141
1
9
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Hey it actually works, but for the words.length I get aException in thread "main" java.lang.IndexOutOfBoundsException: Index: 5, Size: 5 at java.util.ArrayList.rangeCheck(Unknown Source) at java.util.ArrayList.get(Unknown Source) – David Apr 13 '17 at 07:12
have edited my answer. you have another loop which breaks to early, therefore your node-list is too short. – Markus Apr 13 '17 at 07:15
Now I getException in thread "main" java.lang.IndexOutOfBoundsException: Index: 6, Size: 6 at java.util.ArrayList.rangeCheck(Unknown Source) at java.util.ArrayList.get(Unknown Source) – David Apr 13 '17 at 07:19

elements of string array unable to compare with a string

1 Answers1