Obsolete since JSAPI 42
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
jsval constants that represent the JavaScript values true and false.
Syntax
JSVAL_TRUE JSVAL_FALSE
Description
JSVAL_TRUE and JSVAL_FALSE are jsval constants that represent the JavaScript boolean values, true and false. They are equivalent to BOOLEAN_TO_JSVAL(true)BOOLEAN_TO_JSVAL(false), respectively.
Take care not to confuse the jsval constants JSVAL_TRUE and JSVAL_FALSE with the bool constants true and false. jsval values must not be used as C true/false values; there is no guarantee that the C bit-pattern of any particular jsval is zero or nonzero.