Finding length of all arrays multidimensional array, Java

Question

I would like to use a multidimensional array to store a grid of data. However, I have not found a simple way to find the length of the 2nd part of the array. For example:

boolean[][] array = new boolean[3][5];
System.out.println(array.length);

will only output 3.

Is there another simple command to find the length of the second array? (i.e. output 5 in the same manner)

Solution 1

Try using array[0].length, this will give the dimension you're looking for (since your array is not jagged).

Solution 2

boolean[][] array = new boolean[3][5];

Creates an array of three arrays (5 booleans each). In Java multidimensional arrays are just arrays of arrays:

array.length

gives you the length of the "outer" array (3 in this case).

array[0].length

gives you the length of the first "inner" array (5 in this case).

array[1].length

and

array[2].length

will also give you 5, since in this case, all three "inner" arrays, array[0], array[1], and array[2] are all the same length.

Solution 3

array[0].length would give you 5

Solution 4

int a = array.length;

if (a > 0) {
  int b = array[a - 1].length;
}

should do the trick, in your case a would be 3, b 5

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