MQL5 Multi variables Array structure

Question

How to create an Array on MQL5 that can hold 3 variablesand how to fill it and how to call it? Please see the picture https://i.imgur.com/VyjmwNW.jpg [![array][1]][1]

After nicholishen Answer when i try to Initialize array useing Variables i get the follwing error : 'hi' - constant expression required 22.mq5 16 18

void OnStart()
{
   struct MyData { string name; double price; int volume; };
   // initializing an array of structs


     double hi= 0.01;


   MyData arr[] = {
      {"USDJPY", hi, 200},
      {"USDJPY", 110.100, 300},
      {"USDJPY", 110.200, 400},
   };

}

What do you mean when talking about 3 variables? different types of data (ints and doubles)? or something else? — Daniel Kniaz
so what is the problem? you can have a two-dimensional array, second dimension must be fixed, first can be dynamic and change. e.g. int array[][3]; then add more elements by using ArrayResize function - it is well documented so please show what you did and why it does not work so that we will try to help you wiht your code. — Daniel Kniaz
Daniel thank you for your replay, Just want to understand the array structure in MQL5 — user2767046

nicholishen nicholishen · Accepted Answer · 2019-03-30T22:16:37

What I believe you are looking for is an array of structs. A struct is an object that can hold different types of data. Here is a example you can run in your terminal.

void OnStart()
{
   struct MyData { string name; double price; int volume; };
   // initializing an array of structs
   MyData arr[] = {
      {"USDJPY", 110.000, 200},
      {"USDJPY", 110.100, 300},
      {"USDJPY", 110.200, 400},
   };
   // changing some values 
   arr[1].name = "EURUSD";
   arr[1].price = 1.12;
   arr[1].volume = 1000;

   for (int i=0; i<ArraySize(arr); i++)
      printf(
         "Symbol=%s, price=%.3f, vol=%d", 
         arr[i].name, 
         arr[i].price, 
         arr[i].volume
      );
}

MQL5 Multi variables Array structure

1 Answers