Clearing Internal Tables in ABAP

Created: 12 December 2019

Remember: for internal tables with header line, itab referes to the work area and itab[] refers to the internal table.

	Table with Header Line	Table without Header Line
`REFRESH itab` (obsolete)	Table body is initialized, and not header (equivalent to `CLEAR itab[]`)	Delete all rows of internal table and free space, except for initial memory requirement.
`CLEAR itab`	Only header line is deleted. `CLEAR itab[]` to delete all rows.	Delete all rows of internal table and free space, except for initial memory requirement.
`FREE itab`	Delete all rows of internal table and free entire memory space occupied by rows. Affects table body and not the header line.	Delete all rows of internal table and free entire memory space occupied by rows.