boolean
Casts an object to a boolean.
Syntax

boolean(X)

X
is any object

Description
If X
is any object, boolean(X)
is a boolean with a value that depends on X
, according to the following rules:

If
X
is a number, thenboolean(X)
istrue
iffX
is not (exactly) zero. 
If
X
is a string, then:
If
X
converted to lower case is"true"
, thenboolean(X)
istrue
. 
If
X
converted to lower case is"false"
, thenboolean(X)
isfalse
. 
Otherwise, an error is raised.


If
X
is a container which is not a string, thenboolean(X)
istrue
iff#X > 0
. 
If
X
is a null object, thenboolean(X)
isfalse
. 
If
X
is a success indication, thenboolean(X)
istrue
. 
If
X
is a boolean, thenboolean(X)
isX
. 
If
X
is a binary data object, thenboolean(X)
istrue
iffX
contains at least one nonzero byte. 
If none of the above points apply, then
boolean(X)
istrue
.