C++ Strategy Writing Guide

1. The main difference between writing strategies in C++ and JavaScript lies in the data returned by API functions on the FMZ Quant Trading Platform. For example, the exchange.GetTicker() function:

• JavaScript
  exchange.GetTicker() returns an object when called successfully, and returns null if the call fails (e.g., exchange server issues, network problems, etc.).

  
              javascript
              
              
  function main() {
      var ticker = exchange.GetTicker()
      // Check if exchange.GetTicker function call failed and returned null
      if (ticker){
          Log(ticker)
      }
  }
  

• C++
  exchange.GetTicker() returns an object when called successfully, and still returns an object when the call fails. The objects returned from successful and failed calls are distinguished by the Valid property.

  
              c++
              
              
  void main() {
      auto ticker = exchange.GetTicker();
      // Check if exchange.GetTicker() function call failed by checking if the Valid property in the returned object is false
      if (ticker.Valid) {
          Log(ticker);
      }
  }
  

2. The difference between the main() function in C++ strategies and the main() function in standard C11:
   The entry function main() in C11 C++ programs returns an int type, while in FMZ Quant's C++ strategies, the strategy's startup function is also main(). However, these are not the same function, they just share the same name. The main() function in FMZ Quant's C++ strategies returns a void type.

            c++
            
            
void main() {
    // Test using the Test function
    if (!Test("c++")) {
        // Throw an exception to terminate program execution
        Panic("Please download the latest version of the docker");
    }

    // All returned objects use the Valid property to determine validity
    LogProfitReset();
    LogReset();
    Log(_N(9.12345, 2));
    Log("use _C", _C(exchange.GetTicker), _C(exchange.GetAccount));
}