Truncate with an ellipsis in C#
C# interview exercise on Strings, difficulty 1 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
Write Truncate(s, maxLength) that returns s unchanged if it has at most maxLength characters, otherwise the first maxLength characters followed by "…". Substring and ranges throw when they run past the end, so check the length first.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.