- Program Running
- Trade Permission
- Client Terminal Events
- Resources
- Call of Imported Functions
- Runtime Errors
- Testing Trading Strategies
Runtime Errors
The executing subsystem of the client terminal has an opportunity to save the error code in case it occurs during a MQL5 program run. There is a predefined variable _LastError for each executable MQL5 program.
Before starting the OnInit function, the _LastError variable is reset. In case an erroneous situation occurs during calculations or in the process of internal function calls, the _LastError variable accepts a corresponding error code. The value stored in this variable can be obtained using the GetLastError() function.
There are several critical errors in case of which a program is terminated immediately:
- division by zero
- going beyond array boundary
- using an incorrect object pointer