Named Constants

All constants used in MQL5 can be divided into the following groups:

• Predefined macro substitutions – values are substituted during compilation;
• Mathematical constants – values of some mathematical expressions;
• Numerical type constants –  some of the simple type restrictions;
• Uninitialization reason codes – description of uninitialization reasons;
• Checking Object Pointer – enumeration of types of pointers returned by the CheckPointer() function;
• Other constants – all other constants.