#include <iostream>
#include <map>
#include <string>

using namespace std;

// Function to convert currency
double convertCurrency(double amount, const string& fromCurrency, const string& toCurrency) {
    // Exchange rates (as of a specific date)
    map<pair<string, string>, double> exchangeRates = {
            {make_pair("USD", "EUR"), 0.89},
            {make_pair("USD", "GBP"), 0.77},
            {make_pair("USD", "JPY"), 109.35},
            // Add more exchange rates as needed
    };

    // Check if conversion rates exist for the given currencies
    if (exchangeRates.find(make_pair(fromCurrency, toCurrency)) != exchangeRates.end()) {
        double exchangeRate = exchangeRates[make_pair(fromCurrency, toCurrency)];
        return amount * exchangeRate;
    } else {
        cout << "Conversion not available for the provided currencies." << endl;
        return 0.0;
    }
}

int main() {
    double amount;
    string fromCurrency, toCurrency;

    // Input amount and currencies
    cout << "Enter amount: ";
    cin >> amount;
    cout << "Enter from currency (e.g., USD): ";
    cin >> fromCurrency;
    cout << "Enter to currency (e.g., EUR): ";
    cin >> toCurrency;

    // Convert currency
    double convertedAmount = convertCurrency(amount, fromCurrency, toCurrency);

    // Output result
    if (convertedAmount != 0.0) {
        cout << amount << " " << fromCurrency << " is equivalent to " << convertedAmount << " " << toCurrency << 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
}