MQL5 Multi variables Array structure

External question — Stack Overflow Stack Exchange Author: user2767046 Original post: https://stackoverflow.com/questions/55396573 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. 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.sstatic.net/VspJb.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}, }; }

External answer — Stack Overflow Stack Exchange Author: nicholishen Original post: https://stackoverflow.com/a/55436123 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. 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 ); }

External answer — Stack Overflow Stack Exchange Author: TheLegs Original post: https://stackoverflow.com/a/79951000 License: CC BY-SA 4.0 — https://creativecommons.org/licenses/by-sa/4.0/ Adaptation: HTML converted to plain text; contact email addresses removed. Based on your latest edit, where you are asking about using a variable to initialise the struct, you should consider having a constructor, like you would in a class . You can even overload it. If you define the struct like this: struct MyData { string name; double price; int volume; // Version 1: requires all parameters MyData( string newName, double newPrice, int newVolume ): name(newName), price(newPrice), volume(newVolume) {} // Version 2: you pre-set some values MyData( double newPrice, int newVolume ): price(newPrice), volume(newVolume) { name = _Symbol; } // Default constructor: if you intend to use this // method for an array like MyData data[], this must // also be present MyData() {} }; Then, inside OnStart() , you can call for example: void OnStart() { // ...the code above goes here, or outside this function // This calls the default constructor, leaves it empty MyData test1; // This uses the first method test1 = MyData("AUDCAD", 1.209, 188); // This uses the other method test1 = MyData(1.209, 188); // Both of these ways will work with your variable now double hi = 0.01; test1 = MyData("AUDCAD", hi, 188); test1 = MyData(hi, 188); } But note that with this method, the usual initialisation (like test1 = {"AUDCAD", 1.209, 188} ) will no longer work as per documentation : Classes and structures can have an explicit constructor and destructor. If your constructor is explicitly defined, the initialization of a structure or class variable using the initializing sequence is impossible. By the way, OnStart() is for scripts and services, if your intention is to use an Expert Advisor or an Indicator, you should use OnInit() instead.