read: {name}
write: ^\s*{name}\s+{expression}\s*$
length/setness: {name}\s*?
unset: ^\s*{name}\s*?\s*$
Variable names must start with a letter A-Z or a-z
and can contain these letters, the digits 0-9,
the underscore _ and the single quote ' character.
Set a variable:
varname value
Access a variable:
varname
Check if a variable
is set:
varname ?
-- returns an integer>0 if set, else 0
Get the
length of a string:
strname ?
-- empty strings count as unset
-- numbers are typecast to string before
Unset variable:
varname ?
-- as a full line
System variables (all-uppercase) are
read-only,
they can neither be set nor unset directly
(some may be altered via specific functions).
JS:
x=1
s.length
delete r
PHP:
$x=1;
strlen($s)
unset($r);
Pascal:
x:=1;
Length(s)
r:=nil;
JS:
typeof v !== "undefined"
Pascal:
Assigned(v)
PHP:
isset($v)
Eas:
v?