Since a matrix is simply an array whose elements are themselves arrays, in the initialization of a matrix we can use an expression that denotes a matrix.

*Example:*

int[][] m = { { 3, 5 }, { 1, -2 } };

Note that the definition of the matrix above is equivalent to:

int[][] m = new int[2][2]; m[0][0] = 3; m[0][1] = 5; m[1][0] = 1; m[1][1] = -2;