Question

For some reason I keep getting a error that says “toupper cannot be used as a function”. But to my undersatnding toupper is a global function that converts lowercase chars to uppercase.

#include <cctype>
#include <iostream>              
#include <string>

using namespace std;                

int main ()

{


  string input;
  string output;
  int toupper;

  cout<<"Enter a String of Charchters to be Capitalized : ";
  cin>>input;
  string arrayinput[20]= input;
  output = toupper(arrayinput);
  cout<<"\n\n\n"<<output<<"\n\n\n";



cout<<"Press <Enter> to Exit";
cin.ignore();
cin.get();      
return 0;                        
}

Answer 1

You’ve created a local variable called int toupper – rename that one to something else.

Edit to add:
There are more problems than just this. input is a string; you want to iterate through the length of that string and get char* at each position using string::at(i). Then use atoi to convert the char to an int, which is the type that toupper takes as an argument.