CLEAR Clear or Delete a Variable

Section: Inspection Functions


Clears a set of variables from the current context, or alternately, delete all variables defined in the current context. There are several formats for the function call. The first is the explicit form in which a list of variables are provided:
   clear a1 a2 ...

The variables can be persistent or global, and they will be deleted. The second form

   clear 'all'

clears all variables and libraries from the current context. Alternately, you can use the form:

   clear 'libs'

which will unload any libraries or DLLs that have been imported. Optionally, you can specify that persistent variables should be cleared via:

   clear 'persistent'

and similarly for global variables:

   clear 'global'

You can use

   clear 'classes'

to clear all definitions of user-defined classes. With no arguments, clear defaults to clearing 'all'.


Here is a simple example of using clear to delete a variable. First, we create a variable called a:
--> a = 53

a = 

Next, we clear a using the clear function, and verify that it is deleted.

--> clear a
--> a
Error: Undefined function or variable a