Invocation of this function causes a garbage collection to occur. Garbage collection has the effect of deleting all data to which no references are made. It also cleans the remember tables of procedures with an option system or option builtin by removing entries that have no other references to them.  Note, as of Maple 16 the use of gc is discouraged.

This function returns the value NULL.

In the Command-line interface, the function prints a message showing three values:

where xxxx is the total bytes used, yyyy is the total bytes actually allocated, and zzzz is the total CPU time used (in seconds) since the start of the session.

In the worksheet interfaces, the status bar at the bottom of the window is updated. In the Standard Worksheet interface, Maple updates the Memory value. In the Classic Worksheet interface, Maple updates the Bytes value.

The gc command is thread safe as of Maple 15.  However calling gc requires that all running threads be paused for the gc to occur.