exists — checks variable existence
exists(name [,where])
a character string
an optional character with possible values:
'l' (local), 'n'
(nolocal) and 'a' (all). The default
value is 'all'.
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,'local') returns 1
if the variable named name exists in the environment of
the current function and 0 otherwise.
exists(name,'nolocal') 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.
deff('foo(x)',..
['disp([exists(''a12''),exists(''a12'',''local'')])'
'disp([exists(''x''),exists(''x'',''local'')])'])
foo(1)
a12=[];foo(1)
function level1()
function level2()
disp(exists("a","all"));
disp(exists("a","local"));
disp(exists("a","nolocal"));
endfunction
level2()
endfunction
function go()
a=1;
level1()
endfunction
go()