how to use (String [] [] args) in java [closed]

Answer 1

If you use this construction, how would you pass in the infromations? If it's 1D then the words are seperated by space, but how in 2D case? If you need to pass in 2d matrix you should pass it in from file. public static void main(String [] [] args)

Answer 2

Here is an example of instantiating and accessing members of a two dimensional String array.

public class TwoDimensionalArray {
    public static void main(String[] args) {
        String[][] array = new String[2][];
        array[0] = new String[2];
        array[0][0] = "apple";
        array[0][1] = "cherry";
        array[1] = new String[2];
        array[1][0] = "banana";
        array[1][1] = "grape";
        System.out.println(array[0][0]);
        System.out.println(array[0][1]);
        System.out.println(array[1][0]);
        System.out.println(array[1][1]);
    }
}

This program outputs

apple
cherry
banana
grape

Answer 3

This is a example program that creates a 2d array (called matrix):

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

    // will initialize the matrix with null references
    String[][] matrix = new String[4][3];

    // fill it with some values
    for (int i = 0; i < matrix.length; i++) 
        for (int j = 0; j < matrix[0].length; j++)
            matrix[i][j] = "Hello";

    // set a specific matrix element
    matrix[1][1] = "World";

    // print it
    for (int i = 0; i < matrix.length; i++) 
        System.out.println(Arrays.toString(matrix[i]));
}

It will print:

[Hello, Hello, Hello]
[Hello, World, Hello]
[Hello, Hello, Hello]

Answer 4

String[][] is an array of arrays of Strings. Sometimes that's called a two-dimensional array.

An array of X can be created using new X[] { instanceOfX1, instanceOfX2, instanceOfX3 }.

Since X in this case is String[] you could create a String[][] like this:

new String[][] { new String[] { "a", "b" }, new String[] { "x", "y" }, new String[] { } }

Note that the inner arrays don't need to be of the same size (this is called a jagged array).

Answer 5

Not sure what you mean, but here is an example.

String[][] args = new String[10][10];
// Now you can iterate over arg and do many things.