Foreach with multidimensional arrays in Java

Question

I read Java: The Complete Reference(9th). In Character 5: Control Statements - Iterating Over Multidimensional Arrays section Write:

The enhanced version of the for also works on multidimensional arrays. Remember, however, that in Java, multidimensional arrays consist of arrays of arrays. (For example, a two-dimensional array is an array of one-dimensional arrays.) This is important when iterating over a multidimensional array, because each iteration obtains the next array, not an individual element. Furthermore, the iteration variable in the for loop must be compatible with the type of array being obtained. For example, in the case of a two-dimensional array, the iteration variable must be a reference to a one-dimensional array. In general, when using the for-each for to iterate over an array of N dimensions, the objects obtained will be arrays of N–1 dimensions. To understand the implications of this, consider the following program. It uses nested for loops to obtain the elements of a two-dimensional array in row- order, from first to last.

I can't understand why "to iterate over an array of N dimensions, the objects obtained will be arrays of N–1 dimensions". Is it true?

Answer 1

An array of N dimensions is really an array of (N-1)-dimensional arrays. Therefore, when we iterate over an array of N dimensions, we are iterating over all of its constituent (N-1)-dimensional arrays, as indicated.

For example, consider a 2-dimensional array:

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

This is really an array of 1-dimensional arrays: {1,2,3} and {4,5,6}.