The following is a short sketch with a single new Class. In the class I’m trying to develop a 2D array in the Constructor and then use it in a method in the class. The method recognizes a variable in the constructor but does not recognize any of the elements in the 2D array? It works if you comment …

Sorry … I used the wrong verbiage. You need to allocate them in the constructor using the new keyword. class Level { boolean[][] my2dArr; // declare Level(int arg1, int arg2) { my2dArr = new boolean[arg1][arg2]; // allocate my2dArr[0][0] = true; // define }

Using a 2D Array in a Class Object - NullPointerException?

Processing Beginners

slow_izzm June 5, 2020, 10:26pm 2

these variables have already been declared … you only need to allocate them here.

1 Like

Topic		Replies	Views
NullPointerException with objects Coding Questions	2	339	May 15, 2019
Writing my first Class, and getting in trouble already Beginners	10	327	September 22, 2022
Problem with array of objects from a class Coding Questions	12	598	October 14, 2019
Why can't I access this array within my constructor? Coding Questions	13	749	June 6, 2020
NullPointerException by creating an object Beginners	4	182	November 26, 2022

Using a 2D Array in a Class Object - NullPointerException?

Related topics