exists

Arguments

name

matrix of character strings: names of queried variables.

where

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

ve

a matrix with the same size as name with possible values: 1 if true, 0 if false

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("myNotLikelyToExistVar") myNotLikelyToExistVar = 1; exists("myNotLikelyToExistVar")

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

See also

• isdef — checks variable existence
• isglobal — checks if a local variable has a global counterpart
• whereis — Returns the name of the loaded library/module a given function belongs to
• type — returns the type of a Scilab object
• typeof — explicit type or overloading code of an object
• macrovar — variables of function