/******************************************************************************

                              Online C++ Compiler.
               Code, Compile, Run and Debug C++ program online.
Write your code in this editor and press "Run" button to compile and execute it.

*******************************************************************************/

#include <Windows.h>
#include <wincrypt.h>
#include <exception>
#include <iostream>
#include <locale> 
#include  <codecvt>
 
using namespace std;

    inline void ConvertBinaryToBase64String(const void* buffer,
            std::size_t size,
            std::string& encodedString)
    {
        DWORD lengthWithTerminator = 0;
        BOOL success = CryptBinaryToStringA(
                reinterpret_cast<const BYTE*>(buffer),
                static_cast<DWORD>(size),
				CRYPT_STRING_BASE64 | CRYPT_STRING_NOCRLF,
                nullptr, &lengthWithTerminator);
        if (!success)
        {
            std::string err("Error on getting base64 string length: ");
            err += std::to_string(GetLastError());
            throw std::runtime_error(err);
        }

		encodedString.resize(lengthWithTerminator);
		char* newBuf = &(encodedString[0]);
        success = CryptBinaryToStringA(
                reinterpret_cast<const BYTE*>(buffer),
                static_cast<DWORD>(size),
				CRYPT_STRING_BASE64 | CRYPT_STRING_NOCRLF,
                newBuf, &lengthWithTerminator);
       
        if (!success)
        {
            std::string err("Error on encrypting base64 string: ");
            err += std::to_string(GetLastError());
            throw std::runtime_error(err);
        }

        // Keep only content, no ending '\0'
		encodedString.pop_back();
    }
    
int main()
{
    std::wstring unicodeQuery = L"😭😭😭";
    std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> wstring2UTF8conv;
    std::string query = wstring2UTF8conv.to_bytes(unicodeQuery);
    
    std::string base64string;
    ConvertBinaryToBase64String(query.c_str(), query.size(),base64string);
    
        std::cout << base64string << std::endl;
    
    return 0;
}

C++ Online Compiler

Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!

Read inputs from stdin

OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

#include <iostream>
#include <string>
using namespace std;

int main() 
{
    string name;
    cout << "Enter name:";
    getline (cin, name);
    cout << "Hello " << name;
    return 0;
}

About C++

C++ is a widely used middle-level programming language.

  • Supports different platforms like Windows, various Linux flavours, MacOS etc
  • C++ supports OOPS concepts like Inheritance, Polymorphism, Encapsulation and Abstraction.
  • Case-sensitive
  • C++ is a compiler based language
  • C++ supports structured programming language
  • C++ provides alot of inbuilt functions and also supports dynamic memory allocation.
  • Like C, C++ also allows you to play with memory using Pointers.

Syntax help

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition If-Else is used.

if(conditional-expression) {
   //code
}
else {
   //code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression){    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
......    
    
default:     
 code to be executed when all the above cases are not matched;    
}

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement){  
  //code  
}

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while (condition) {  
// code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {  
 // code 
} while (condition);

Functions

Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.

How to declare a Function:

return_type function_name(parameters);

How to call a Function:

function_name (parameters)

How to define a Function:

return_type function_name(parameters) {  
 // code
}