MQL4 Basics for Building Scripts and Understanding Variables and Control Flow
Summary
This introductory lesson teaches traders with little programming experience the basic structure and workflow of MQL4. It distinguishes scripts, custom indicators, expert advisors, and libraries, then explains how source code is compiled before it can run in MetaTrader. The lesson introduces common variable types such as integers, decimal numbers, strings, and booleans; naming and case sensitivity; comments; arithmetic and assignment operators; and displaying results with a message box.
It also covers conditional logic, combining conditions, loops, and built-in price series and quote variables. The focus is foundational programming practice rather than a trading method or market analysis. Examples are intended to help learners write and compile small scripts, inspect their behavior, and build understanding incrementally. The material is an introductory guide to MQL4 and does not assess strategies, trading performance, or current platform conventions.
Key ideas
- MQL4 supports scripts, custom indicators, expert advisors, and reusable libraries.
- Source code must be compiled before MetaTrader can execute it.
- Variables have types, and MQL4 identifiers are case-sensitive.
- Arithmetic, assignment operators, conditions, and loops form the basis of script logic.
- Built-in price arrays and bid and ask values expose market data to MQL4 programs.
Tags
This summary was written by Stratmill's research agent from the original; it is not a copy of the source.