I was tasked with writing code that would convert strings into their initials via a function. For example, running "Dog" and "Cat" through the function would yield an output of "D. C.". However, another component of the task is that the code must require at least 2 strings to run. This is where I'm getting stuck.
Here's my code which works fine, just missing the "require 2 strings to run" part. Any suggestions for optimizing the code would be helpful as well.
#include <iostream>
#include <string>
#include <string.h>
using namespace std;
string initials(string&, string&, string&, string&, string&);
int main()
{
string a = "This";
string b = "Is";
string c = "A";
string d = "Test";
string e = "Run";
initials(a, b, c, d, e);
cout << a << ". " << b << ". " << c << ". " << d << ". " <<e;
}
string initials(string& a, string& b, string& c, string& d, string& e) {
a = a[0];
b = b[0];
c = c[0];
d = d[0];
e = e[0];
return a;
return b;
return c;
return d;
return e;
}
My code only allows for 5 strings to go through the function, but it also has to require at least 2 for the code to run. The output for the provided code yields "T. I. A. T. R.", which is what I wanted. However, the code below also runs fine. How can I force the code to only run if there are at least two strings run through the function?
#include <iostream>
#include <string>
#include <string.h>
using namespace std;
string initials(string&, string&, string&, string&, string&);
int main()
{
string a = "This";
string b;
string c;
string d;
string e;
initials(a, b, c, d, e);
cout << a << ". " << b << ". " << c << ". " << d << ". " <<e;
}
string initials(string& a, string& b, string& c, string& d, string& e) {
a = a[0];
b = b[0];
c = c[0];
d = d[0];
e = e[0];
return a;
return b;
return c;
return d;
return e;
}
CodePudding user response：
Welcome to C !
Modern C takes optional parameters. In addition, you should probably revisit the basics of how functions return in the language. Multiple return statements are ignored after the first one.
This should work:
#include <iostream>
#include <string>
#include <string.h>
using namespace std;
string initials(string first, string second, string third = "", string fourth = "", string fifth = "");
int main()
{
string a = "This";
string b = "Are";
string c = "My";
string d = "Name";
string e = "Initials";
cout << initials(a, b, c, d, e) << endl;
cout << initials("John", "Smith") << endl;
}
string initials(string first, string second, string third, string fourth, string fifth) {
string result = string(1, first.at(0)) ". ";
result = string(1, second.at(0)) ". ";
result = third == "" ? "" : string(1, third.at(0)) ". ";
result = fourth == "" ? "" : string(1, fourth.at(0)) ". ";
result = fifth == "" ? "" : string(1, fifth.at(0)) ". ";
return result;
}
Note that I removed the references & from the function signature. I'll leave it up to you to try what happens if you keep them :)
If you've learned arrays already, you should notice that the implementation of initials could easily be generalized to an array of N names.
CodePudding user response：
variadic template might help for your 2 or more restriction:
void make_initial(std::string& s)
{
if (!s.empty()) { s.resize(1); }
}
template <typename... Strings>
requires(sizeof...(Strings) >= 2 && (std::is_same_v<std::string, Strings> && ...))
void initials(Strings&... strings)
{
(make_initial(strings), ...);
}