Multidimensional Arrays

Multidimensional Arrays

A multidimensional array consists of arrays within arrays.

Multidimensional arrays prove useful when organizing data in a tabular format, resembling a table comprising rows and columns.

You can form a two-dimensional array by enclosing each array within its own set of curly braces:

Example

int[][] myNumbers = { {1, 2, 3, 4}, {5, 6, 7} };

Now, myNumbers consists of an array containing two arrays as its elements.

Access Elements

To retrieve elements from the myNumbers array, you need to provide two indexes: one for the array and another for the element within that array. In this instance, the example accesses the third element (2) in the second array (1) of myNumbers.

Example

int[][] myNumbers = { {1, 2, 3, 4}, {5, 6, 7} };
System.out.println(myNumbers[1][2]); // Outputs 7

Change Element Values

You also have the capability to modify the value of an element:

Example

int[][] myNumbers = { {1, 2, 3, 4}, {5, 6, 7} };
myNumbers[1][2] = 9;
System.out.println(myNumbers[1][2]); // Outputs 9 instead of 7

Loop Through a Multi-Dimensional Array

int[][] myNumbers = { {1, 2, 3, 4}, {5, 6, 7} };
for (int i = 0; i < myNumbers.length; ++i) {
  for (int j = 0; j < myNumbers[i].length; ++j) {
    System.out.println(myNumbers[i][j]);
  }
}

int[][] myNumbers = { {1, 2, 3, 4}, {5, 6, 7} };
for (int[] row : myNumbers) {
for (int i : row) {
    System.out.println(i);  
  }
}