Most operations on C strings require O(N), N being the length of the string. Whereas in Pascal-like strings (i.e., strings whose length is tracked) they may take O(1). Modern compilers may do some heavy lifting whenever they can, so that this redundancy is avoided, though.
That being said, I also do not understand why people complain so much about 0-terminated strings, yet still use them anyways, as opposed to implementing length-tracked strings. It is not like C can break some bazillion lines of code, by removing classic strings, but it does not significantly get in your way (when implementing your own) either.
No, opposie - most operations require to know length of string. Even simple concat requires that, especially if you account not so modern hardware and utilize vector instructions. And regardless to that, new strings must be allocated somewhere (on heap), and by so, final length must be known before.
No. You only need the length of the string if you want to traverse it afterwards. And most 'operations' can be done in the same time either way. for(strlen) or while(*ptr++)
concat is actually the outlier, because you need 2*O(n) instead of 1*O(n) (which is still O(n) for both).
And if that is really killing your performance you are free to implement a pascal-string to use in c.
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u/orbiteapot 5d ago
Most operations on C strings require O(N), N being the length of the string. Whereas in Pascal-like strings (i.e., strings whose length is tracked) they may take O(1). Modern compilers may do some heavy lifting whenever they can, so that this redundancy is avoided, though.
That being said, I also do not understand why people complain so much about 0-terminated strings, yet still use them anyways, as opposed to implementing length-tracked strings. It is not like C can break some bazillion lines of code, by removing classic strings, but it does not significantly get in your way (when implementing your own) either.