Literals in expressions are literal values that can be:
A number.
A string (can be enclosed in double ("") or single ('') quotation marks).
A character (any one-character string).
The JADE-defined (that is, system-defined)
true
false
Use these true and false system-defined Boolean literal values to initialize a Boolean variable.
The JADE-defined null literal, which represents the null, or uninitialized, state of primitive type values or object references. Use the system-defined null literal to initialize an object reference or compare for an empty object, as shown in the code fragments in the following examples.
if customer <> null then customer.name := "John Doe"; endif; if customer = null then write "Uninitialized customer"; else write customer.name; endif;
See also "StringUtf8 Literals", "Type of a Numeric Literal", and "Hexadecimal Literals", in the following subsections.