Named Constants

All constants used in MQL4 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.