Question

I want to make a loop on Two-dimensional array in Java.

How I do that? I wrote:

    for (int i = 0; i<=albums.size() - 1; i++){
        for (int j = 0; j<=albums.size() - 1; j++){

But it didn’t work. Thanks.

Answer 1

Arrays have a read-only field called length, not a method called size. A corrected loop looks like this:

for(int i = 0; i < albums.length; i++ ) {
    for (int j = 0; j < albums[i].length; j++) {
        element = albums[i][j];

You have to recognize that a 2-D array is just an array whose element type happens to be another array. So the i loop iterates over each element in albums (which is an array) and the j loop iterates over that child array (with a potentially different size).

A more transparent way would be like this:

String[][] albums;

for(int i = 0; i < albums.length; i++ ) {
    String[] childArrayAtI = albums[i];
    for (int j = 0; j < childArrayAtI.length; j++) {
        String element = childArrayAtI[j];
    }
}