public class Undefined
extends java.lang.Object
implements java.io.Serializable
We represent "undefined" internally using two static objects -- "Undefined.instance" and SCRIPTABLE_UNDEFINED. Java code that needs to make something undefined should generally use the first, and use the second if a Scriptable object is absolutely required.
Java code that needs to test whether something is undefined must use the "isUndefined" method because of the multiple internal representations.
Modifier and Type | Field and Description |
---|---|
static java.lang.Object |
instance
This is the standard value for "undefined" in Rhino.
|
static Scriptable |
SCRIPTABLE_UNDEFINED
An alternate representation of undefined, to be used only when we need to pass it to a method
that takes as Scriptable as a parameter.
|
Modifier and Type | Method and Description |
---|---|
boolean |
equals(java.lang.Object obj) |
int |
hashCode() |
static boolean |
isUndefined(java.lang.Object obj)
Safely test whether "obj" is undefined.
|
java.lang.Object |
readResolve() |
public static final java.lang.Object instance
public static final Scriptable SCRIPTABLE_UNDEFINED
public java.lang.Object readResolve()
public boolean equals(java.lang.Object obj)
equals
in class java.lang.Object
public int hashCode()
hashCode
in class java.lang.Object
public static boolean isUndefined(java.lang.Object obj)