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Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today. I keep getting errors regarding = inn lines 12 and 14, but no clues. Can anyone please help?

Math.cs
```namespace Treehouse.CodeChallenges
{
public static class MathHelpers
{
public static int[][] BuildMultiplicationTable(int maxFactor)
{
int arraySize = maxFactor + 1;
int[][] BuildMultiplicationTable = new int[arraySize][];

BuildMultiplicationTable[arraySize] = new int[arraySize];

for (int i=0, i < maxFactor; i++)
{
for (int j=0, j < maxFactor; j++)
{
table[i][j] = i * j;
}
}

return table;

}
}
}
```

You have a comma instead of a semicolon in `for (int i=0, i < maxFactor; i++)` and `for (int j=0, j < maxFactor; j++)`. You also have not declared `table`. Aha - thanks! My update as follows, but it says..."Bummer: Index was outside the bounds of the array."

namespace Treehouse.CodeChallenges { public static class MathHelpers { public static int[][] BuildMultiplicationTable(int maxFactor) { int arraySize = maxFactor + 1; int[][] BuildMultiplicationTable = new int[arraySize][];

```        BuildMultiplicationTable[arraySize] = new int[arraySize];

for (int i=0; i < maxFactor; i++)
{
for (int j=0; j < maxFactor; j++)
{
BuildMultiplicationTable[i][j] = i * j;
}
}

return BuildMultiplicationTable;

}
}
```

}

In the line `BuildMultiplicationTable[arraySize] = new int[arraySize];`, `arraySize` is outside the bounds of the array because the indices start at `0` and go to `arraySize-1`. If you used `maxFactor` as the index instead, then it would only set the dimension of the last inner array. To set the dimension of each of the inner arrays, you could instead define the size of each inner array inside the outer for loop by setting the index to `i`.

In both the for loops, you might want to change from the form `i < maxFactor` to `i <= maxFactor` or `i < arraySize` so that `maxFactor` is included in the calculations. Thanks so much JB! I tried again, but the same error I got...any clue may I ask? Thanks a bunch!

==

namespace Treehouse.CodeChallenges { public static class MathHelpers { public static int[][] BuildMultiplicationTable(int maxFactor) { int[][] BuildMultiplicationTable = new int[maxFactor][];

```        BuildMultiplicationTable[maxFactor] = new int[maxFactor];

for (int i=0; i <= maxFactor; i++)
{
for (int j=0; j <= maxFactor; j++)
{
BuildMultiplicationTable[i][j] = i * j;
}
}

return BuildMultiplicationTable;

}
}
```

}

In the line `int[][] BuildMultiplicationTable = new int[maxFactor][];`, the number of arrays in the first dimension of `BuildMultiplicationTable` is set to `maxFactor`. Based on the challenge example output, the challenge is expecting there to be `maxFactor + 1` arrays in the first dimension of `BuildMultiplicationTable`. Try changing it back to `int[][] BuildMultiplicationTable = new int[maxFactor + 1][];`

If `BuildMultiplicationTable` has at least `maxFactor + 1` elements in its first dimension, then the line `BuildMultiplicationTable[maxFactor] = new int[maxFactor];` sets the length of an array at `BuildMultiplicationTable[maxFactor]`. It does not set the length of an array at any other index of `BuildMultiplicationTable`. For example, if `maxFactor` is not `0`, the length of an array at `BuildMultiplicationTable` has not been defined, so any index `j` for `BuildMultiplicationTable[j]` will be outside the bounds of the array `BuildMultiplicationTable`.

You could use a for loop to define each of the arrays in the array `BuildMultiplicationTable` by

```for (int i = 0; i <= maxFactor; i++)
{
BuildMultiplicationTable[i] = new int[maxFactor + 1];
}
```

which defines the length of an inner array at each element of the first dimensional array in `BuildMultiplicationTable`. For anyone curious about how this ended with JB's help.

==

namespace Treehouse.CodeChallenges { public static class MathHelpers { public static int[][] BuildMultiplicationTable(int maxFactor) { int[][] BuildMultiplicationTable = new int[maxFactor + 1][]; for (int i=0; i <= maxFactor; i++) { BuildMultiplicationTable[i] = new int[maxFactor+ 1 ];

```                for (int j=0; j <= maxFactor; j++)
{
BuildMultiplicationTable[i][j] = i*j;
}
}

return BuildMultiplicationTable;
}
}
```

}