C++ Program:

Example:

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

#include <iostream>
using namespace std;

int main() {
  char c='A';
  cout<<"Alphabets from A to Z"<<endl;
  for(int i=0; i<26; i++)
    cout<<c++<<" ";
  return 0;
}

Output:

Alphabets from A to Z :
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Here, we just used 'for loop' for 26 alphabet characters

char c='A'; //set the 1st character 
for(int i=0; i<26; i++)
  cout<<c++<<" ";

You can print the same in small alphabets, just set c='a'