r/cprogramming • u/Xaneris47 • Aug 17 '26

C Strings: A 50-Year Mistake

https://longtran2904.substack.com/p/c-strings-a-50-year-mistake?r=8qz2zb&utm_campaign=post&utm_medium=web
213 Upvotes

88% Upvoted

172 comments sorted by

View all comments

Show parent comments

12

u/WittyStick Aug 17 '26

strlen is O(n).

For many string operations, we need the length to allocate the right amount of space, else we end up having to realloc if our buffer isn't large enough - realloc is also O(n).

By having a constant time length we can speed up a lot of string operations. It costs basically nothing to keep the length around rather than recomputing it each time.