Backreferenced vs Null - What's the difference?
backreferenced | null |
(backreference)
(computing) An item in a regular expression equivalent to the text matched by an earlier pattern in the expression.
* 2003 , Rob Brooks-Bilson, Programming ColdFusion MX
* 2005 , Ivan Ristic, Apache security
(computing) To access (the text matched by an earlier pattern in a regular expression).
* 2009 , Larry Ullman, Ruby: Visual QuickStart Guide (page 237)
* 2012 , Tom Christiansen, brian d foy(SIC), Larry Wall, Programming Perl (page 46)
A non-existent or empty value or set of values.
Zero]] quantity of [[expression, expressions; nothing.
Something that has no force or meaning.
(computing) the ASCII or Unicode character (), represented by a zero value, that indicates no character and is sometimes used as a string terminator.
(computing) the attribute of an entity that has no valid value.
One of the beads in nulled work.
(statistics) null hypothesis
Having no validity, "null and void"
insignificant
* 1924 , Marcel Proust, Within a Budding Grove :
absent or non-existent
(mathematics) of the null set
(mathematics) of or comprising a value of precisely zero
(genetics, of a mutation) causing a complete loss of gene function, amorphic.
As a verb backreferenced
is (backreference).As a noun null is
zero, nil; the cardinal number before einn.backreferenced
English
Verb
(head)backreference
English
Alternative forms
* back-referenceNoun
(en noun)- The third part of the regular expression, \1, is the backreference and tells ColdFusion to refer back to the first subexpression
- Path traversal occurs when directory backreferences are used in a path to gain access to the parent folder of a subfolder.
Verb
(backreferenc)- By wrapping it in parentheses, the attributes can be reused by backreferencing this part of the pattern
- It doesn't change what the part matches, so
/\d+/and/(\d+)/will still match as many digits as possible, but in the latter case they will be remembered in a special variable to be backreferenced later.
null
English
Noun
(en noun)- (Francis Bacon)
- Since no date of birth was entered for the patient, his age is null .
Adjective
(en adjective)- In proportion as we descend the social scale our snobbishness fastens on to mere nothings which are perhaps no more null than the distinctions observed by the aristocracy, but, being more obscure, more peculiar to the individual, take us more by surprise.