Why is Count not an unsigned integer? [duplicate]

Answer 1

1. It's not CLS compliant, largely to allow wider support from different languages.

2. A signed int offers ease in porting code from C or C++ that uses pointer arithmetic.

3. Count can be part of an expression where the overall value can be negative. In particular, count has a direct relationship to indices, where valid indices are always in the range [0, Count - 1], but negative results are used e.g. by some binary search methods (including those provided by the BCL) to reflect the position where a new item should be inserted to maintain order.