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Please note that the recommended version of Scilab is 6.0.1. This page might be outdated.
See the recommended documentation of this function

Scilab help >> Scilab > Variables > exists

exists

checks variable existence

Calling Sequence

ve = exists(name [,where])

Arguments

ve

Output result with possible values: 1 if true, 0 if false

name

a character string

where

an optional character with possible values: 'l' (local), 'n' (nolocal) and 'a' (all). The default value is 'a'.

Description

exists(name) returns 1 if the variable named name exists and 0 otherwise.

Caveats: a function which uses exists may return a result which depends on the environment!

exists(name,'l') returns 1 if the variable named name exists in the environment of the current function and 0 otherwise.

exists(name,'n') returns 1 if the variable named name exists in any level of the calling environment (including the Scilab shell main level) of the current function and 0 otherwise.

Warning: the exists function does not check if a variable exists in the global namespace.

Examples

exists("myNotLikelyToExistVariable")
myNotLikelyToExistVariable = 1;
exists("myNotLikelyToExistVariable")
deff('foo(x)',..
['disp([exists(''a12''),exists(''a12'',''l'')])'
 'disp([exists(''x''),exists(''x'',''l'')])'])
foo(1)
a12=[];foo(1)

function level1()
  function level2()
    disp(exists("a","a"));
    disp(exists("a","l"));
    disp(exists("a","n"));
  endfunction
  level2()
endfunction
function go()
  a=1;
  level1()
endfunction
go()

See Also

  • isdef — checks variable existence
  • isglobal — check if a variable is global
  • whereis — name of library containing a function
  • type — returns the type of a variable
  • typeof — object type
  • macrovar — variables of function
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Last updated:
Mon Oct 01 17:34:35 CEST 2012