string c++ replace
#include <cassert>
#include <cstddef>
#include <iostream>
#include <string>
#include <string_view>
std::size_t replace_all(std::string& inout, std::string_view what, std::string_view with);
std::size_t remove_all(std::string& inout, std::string_view what);
void test_replace_remove_all();
int main()
{
std::string str{"The quick brown fox jumps over the lazy dog."};
str.replace(10, 5, "red"); // (5)
str.replace(str.begin(), str.begin() + 3, 1, 'A'); // (6)
std::cout << str << "\n\n";
test_replace_remove_all();
}
std::size_t replace_all(std::string& inout, std::string_view what, std::string_view with)
{
std::size_t count{};
for (std::string::size_type pos{};
inout.npos != (pos = inout.find(what.data(), pos, what.length()));
pos += with.length(), ++count) {
inout.replace(pos, what.length(), with.data(), with.length());
}
return count;
}
std::size_t remove_all(std::string& inout, std::string_view what) {
return replace_all(inout, what, "");
}
void test_replace_remove_all()
{
std::string str2{"ftp: ftpftp: ftp:"};
std::cout << "#1 " << str2 << '\n';
auto count = replace_all(str2, "ftp", "http");
assert(count == 4);
std::cout << "#2 " << str2 << '\n';
count = replace_all(str2, "ftp", "http");
assert(count == 0);
std::cout << "#3 " << str2 << '\n';
count = remove_all(str2, "http");
assert(count == 4);
std::cout << "#4 " << str2 << '\n';
}