Turn a product title into a URL slug
The catalogue builds a URL from each product title, and the result has to be safe to put in a path.
- Lowercase, and keep only letters a-z and digits.
- Every run of anything else collapses to a single dash.
- No dash at the start or the end.
- A title with nothing usable in it gives an empty string.
slugify(title: string) → string
C++ needs a compiler and Drill does not host one yet, so this page is the reference rather than an exercise: the problem, worked examples, and the solution in full. To type it out, the same problem runs in Python.
Where you start
std::string slugify(std::string title) {
}Worked examples
| Call | Result |
|---|---|
slugify(std::string(" Blue Widget, 12mm! ")) | std::string("blue-widget-12mm") |
slugify(std::string("A---B")) | std::string("a-b") |
slugify(std::string("Already-slugged")) | std::string("already-slugged") |
slugify(std::string("!!!")) | std::string("") |
Hint
Append a dash only when there is already something to separate, then trim the one you may have left on the end.
Reference solution in C++
std::string slugify(std::string title) {
string result;
for (char raw : title) {
char ch = static_cast<char>(tolower(static_cast<unsigned char>(raw)));
if ((ch >= 'a' && ch <= 'z') || (ch >= '0' && ch <= '9')) result += ch;
else if (!result.empty() && result.back() != '-') result += '-';
}
if (!result.empty() && result.back() == '-') result.pop_back();
return result;
}