Ask AI: please make a sample expert advisor for mq4

Certainly, I can help you with a basic example of an Expert Advisor (EA) for MetaTrader 4 (MT4) using the MQL4 programming language. Below is a sample EA that implements a simple moving average crossover strategy. This strategy will create buy and sell orders based on the crossover of two moving averages. ```mql4 //+------------------------------------------------------------------+ //| SimpleEA.mq4 | //| Copyright 2023 | //| Your Name | //+------------------------------------------------------------------+ #property strict // Input parameters input int FastMAPeriod = 12; // Period of the fast moving average input int SlowMAPeriod = 26; // Period of the slow moving average input double LotSize = 0.1; // Size of each trade input int Slippage = 3; // Slippage for order execution input double TakeProfitPoints = 50; // Take profit in points input double StopLossPoints = 50; // Stop loss in points int ticket; double EMAFast; double EMASlow; //+------------------------------------------------------------------+ //| Expert initialization function | //+------------------------------------------------------------------+ int OnInit() { // Print a message in the Expert tab Print("EA initialized"); // Return initialization result return(INIT_SUCCEEDED); } //+------------------------------------------------------------------+ //| Expert deinitialization function | //+------------------------------------------------------------------+ void OnDeinit(const int reason) { // Print a message in the Expert tab Print("EA deinitialized"); } //+------------------------------------------------------------------+ //| Expert tick function | //+------------------------------------------------------------------+ void OnTick() { // Calculate the moving averages EMAFast = iMA(NULL,0,FastMAPeriod,0,MODE_EMA,PRICE_CLOSE,0); EMASlow = iMA(NULL,0,SlowMAPeriod,0,MODE_EMA,PRICE_CLOSE,0); double EMAFastPrev = iMA(NULL,0,FastMAPeriod,0,MODE_EMA,PRICE_CLOSE,1); double EMASlowPrev = iMA(NULL,0,SlowMAPeriod,0,MODE_EMA,PRICE_CLOSE,1); // Check for a buy crossover if (EMAFast > EMASlow && EMAFastPrev <= EMASlowPrev) { // Close any open sell orders CloseOrders(OP_SELL); // Open a buy order ticket = OrderSend(Symbol(), OP_BUY, LotSize, Ask, Slippage, 0, 0, "Buy Order", MAGIC_NUMBER, 0, Blue); if(ticket < 0) Print("Error opening BUY order: ", GetLastError()); else Print("BUY order opened successfully"); } // Check for a sell crossover if (EMAFast < EMASlow && EMAFastPrev >= EMASlowPrev) { // Close any open buy orders CloseOrders(OP_BUY); // Open a sell order ticket = OrderSend(Symbol(), OP_SELL, LotSize, Bid, Slippage, 0, 0, "Sell Order", MAGIC_NUMBER, 0, Red); if(ticket < 0) Print("Error opening SELL order: ", GetLastError()); else Print("SELL order opened successfully"); } } //+------------------------------------------------------------------+ //| Function to close orders | //+------------------------------------------------------------------+ void CloseOrders(int orderType) { for (int i=OrdersTotal()-1; i>=0; i--) { if (OrderSelect(i, SELECT_BY_POS, MODE_TRADES)) { if (OrderType() == orderType && OrderSymbol() == Symbol()) { OrderClose(OrderTicket(), OrderLots(), OrderClosePrice(), Slippage, clrNONE); } } } } //+------------------------------------------------------------------+ ``` ### Explanation of the EA: 1. **Input Parameters:** - `FastMAPeriod` and `SlowMAPeriod`: These determine the periods for the fast and slow moving averages. - `LotSize`: The size of each trade in lots. - `Slippage`: The acceptable slippage in points. - `TakeProfitPoints` and `StopLossPoints`: The take profit and stop loss levels in points. 2. **OnInit and OnDeinit Functions:** - These functions handle the initialization and deinitialization tasks respectively. 3. **OnTick Function:** - This function is executed on every tick. - It calculates the moving averages and checks for a crossover. - If a crossover is detected, it closes any existing opposite orders and opens a new order in the direction of the crossover. 4. **CloseOrders Function:** - This function closes orders of a specified type (buy or sell). Before using this EA on a live account, it's important to test it thoroughly on a demo account to ensure it behaves as expected. Additionally, you may need to add more error handling and risk management based on your trading strategy and risk tolerance.