 | JavaScript | |||
|---|---|---|---|---|
| Prev | Home | Up | Next |
The undefined type has exactly one value, called undefined. It is returned by variables that have not yet been assigned with a value.
This value is also returned in some browsers when referring to a part of the document object model that is non-existent.
Sending a subsequent message to values that are currently undefined results in a run-time error.
| See also: | Cast operator, Special type, Type |
ECMA 262 edition 2 - section - 4.3.10
ECMA 262 edition 2 - section - 8.1
ECMA 262 edition 3 - section - 4.3.10
ECMA 262 edition 3 - section - 8.1
Wrox Instant JavaScript - page - 14
| Prev | Home | Next |
| Undefined behaviour | Up | Undocumented features |
JavaScript Programmer's Reference, Cliff Wootton Wrox Press (www.wrox.com) Join the Wrox JavaScript forum at p2p.wrox.com Please report problems to support@wrox.com © 2001 Wrox Press. All Rights Reserved. Terms and conditions. | ||