Create an Expert Advisor
The first thing needed to code an expert advisor is variables. Variables can be declared globally or locally. A global variable is declared at the beginning of your code, before the OnInit() function.
What is an Expert Advisor? When an Algorithmic Trader approaches for the first time in implementing an expert advisor for Metatrader, even before studying all the syntax and MQL code instructions, needs to know some basic principles of general operation.