Using the "Autograder"

Git includes a useful feature that allows for easy, automated testing of code. This testing serves two purposes: it allows graders to easily verify that your code compiled and it allows students to compare the output of their program to the correct output.
Aside from verifying compilation, this tool is not used for grading purposes (even though it's called the "autograder").

This tool runs automatically every time you submit your code via git. You can see the output from the GitHub website. If all of the tests pass, there will be a green checkmark above the list of files:

If there is a red X, that means your tests did not pass. You can click on the red X, then the Details link for more information:

There may be multiple tests with different names. Tests which pass will have a green check:

Tests which don't pass will have a red X:

Your program's output is above the error message:

The expected output is below, but doesn't include any endline characters (so it looks pretty jumbled):

It can be difficult to find the difference if it's a matter of spacing, in which case you don't need to worry; it won't affect your grade. Make sure that the output values match, though, so you can verify that any processing your program does is correct. For example above, the issue is a typo in the header row. The output values match, though, so this program would get a high grade.