C# C# Collections Arrays Jagged Arrays

Loïc Brach
Loïc Brach
239 Points

I do not understand why the function return is null

Can someone give me more informations ?

Math.cs
namespace Treehouse.CodeChallenges
{
    public static class MathHelpers
    {
        public static int[][] BuildMultiplicationTable(int maxFactor)
        {
            int[][] MultiplicationTable = new int[maxFactor+1][];
            for (int i=0;i<maxFactor;i++){
                MultiplicationTable[i] = new int[maxFactor+1];
                for (int j=0;j<maxFactor;j++){
                    MultiplicationTable[i][j]=i*j;
                } 
            }
            return(MultiplicationTable);
        }
    }

}

1 Answer

Steven Parker
Steven Parker
172,140 Points

:point_right: It's some of your cells that are null.

You sized your table correctly by adding one to maxFactor, but when you iterate through the cells to fill them, you stop short of the last row and column. The condition expressions should compare with "less than or equal" ("<=") instead of "less than" ("<").

Loïc Brach
Loïc Brach
239 Points

Thanks a lot Steven