CODEWITHSUNDEEP
javaarraysfile
justanordinaryguy
justanordinaryguy

Reputation: 97

Why hasNextInt() returning false over here?

I have file MatrixToCsv.csv like this:

67,85,20,87,78,46,66;
33,66,88,24,90,28,19;
76,22,46,33,10,16,73;
16,79,28,98,67,49,62;
85,75,12,18,92,58,80;
59,89,16,10,52,67,35;
54,66,62,53,39,91,37;

And i want to save it to an array but only the integers, so I have written this:

public static void main(String[] args) throws IOException {

    Scanner input = new Scanner (new File("MatrixToCsv.csv"));
    int rows = 7;
    int columns = 7;
    int[][] array = new int[rows][columns];

    input.useDelimiter(Pattern.compile(",|;|(\\n)"));
    for(int i = 0; i < rows; ++i)
    {
        for(int j = 0; j < columns; ++j)
        {
            if(input.hasNextInt())
            {
                array[i][j] = input.nextInt();
            }  
        }
    }

    for(int i = 0; i < rows; i++) {
        for (int j = 0; j < array.length; j++) {
            System.out.print(array[i][j]+ " ");
        }
        System.out.println();
    }
    input.close();
}

And the output is:

 67 85 20 87 78 46 66 
    0 0 0 0 0 0 0 
    0 0 0 0 0 0 0 
    0 0 0 0 0 0 0 
    0 0 0 0 0 0 0 
    0 0 0 0 0 0 0 
    0 0 0 0 0 0 0

And I am wondering why it reads only one line from text. Thanks. Q.

Upvotes: 0

Views: 64

Answers (1)

BackSlash
BackSlash

Reputation: 22243

input.useDelimiter(Pattern.compile(",|;|(\\n)"));

Here, you are basically saying that the delimiter can be a single comma OR a single semicolon OR a single newline character.

At the end of each line you have both semicolon and newline, which is not what you set your scanner to use as delimiter. Use [,;\\n]+ instead, which means "one between ,, ; and \n repeated at least one time". This way you'll match ;\n too.

input.useDelimiter(Pattern.compile("[,;\\n]+"));

See it in action

Upvotes: 3

Related Questions