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Scilab Help >> Scilab > Variables > clear


kills variables


clear a b c
clear('a', 'b', 'c')
clear(['a' 'b' 'c'])


a, b, c...

variables of any type and size, but not protected


This command kills variables which are not protected. It removes the named variables from the environment. By itself clear kills all the variables except the variables protected by predef. Thus the two commands predef(0) and clear remove all the variables.

Normally, protected variables are standard libraries and variables with the percent prefix.

Note the particular syntax clear a and clear('a') and not clear(a). Note also that a=[] does not kill a but sets a to an empty matrix.

The command clear can kill nonexistent variables, i. e. clear kills nonexistent variables as if they exist.


a = 2;
b = 3;
c = 4;
clear a
isdef("a") // F
isdef("b") // T
isdef("b") // F

a = 2;
b = 3;
c = 4;
clear(['a' 'b' 'c'])
isdef("a") | isdef("b") | isdef("c") // F

See also

  • predef — variable protection
  • funcprot — switch scilab functions protection mode
  • who — listing of variables


5.5.0 Argument can now be a matrix of strings
6.0.0 clear is now protected: Assignments like clear=1 are no longer possible.
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Last updated:
Thu Feb 14 14:57:07 CET 2019