I need to get the length of a 2D array for both the row and column. I’ve successfully done this, using the following code:
public class MyClass {
public static void main(String args[])
{
int[][] test;
test = new int[5][10];
int row = test.length;
int col = test[0].length;
System.out.println(row);
System.out.println(col);
}
}
This prints out 5, 10 as expected.
Now take a look at this line:
int col = test[0].length;
Notice that I actually have to reference a particular row, in order to get the column length. To me, this seems incredibly ugly. Additionally, if the array was defined as:
test = new int[0][10];
Then the code would fail when trying to get the length. Is there a different (more intelligent) way to do this?
ベストアンサー1
Consider
public static void main(String[] args) {
int[][] foo = new int[][] {
new int[] { 1, 2, 3 },
new int[] { 1, 2, 3, 4},
};
System.out.println(foo.length); //2
System.out.println(foo[0].length); //3
System.out.println(foo[1].length); //4
}
Column lengths differ per row. If you're backing some data by a fixed size 2D array, then provide getters to the fixed values in a wrapper class.