IT. Expert System.

Java Script

RegExp Object Overview


RegExp Object Overview

A regular expression is an object that describes a pattern of characters.

Regular expressions are used to perform pattern-matching and "search-and-replace" functions on text.

Creating a RegExp Object

To create a RegExp object, use the new keyword and assign the result to a variable.

The following example creates a RegExp named 'myRegExp':

var myRegExp = new RegExp(pattern, modifiers);

or

var myRegExp = /pattern/modifiers;
  • pattern specifies the pattern of an expression
  • modifiers specifies if a search should be global, case-sensitive, etc.

Modifiers

Modifiers are used to perform case-insensitive and global searches:

Modifier Description
i Perform case-insensitive matching
g Perform a global match (find all matches rather than stopping after the first match)
m Perform multiline matching

Brackets

Brackets are used to find a range of characters:

Expression Description
[abc] Find any character between the brackets
[^abc] Find any character not between the brackets
[0-9] Find any digit from 0 to 9
[A-Z] Find any character from uppercase A to uppercase Z
[a-z] Find any character from lowercase a to lowercase z
[A-z] Find any character from uppercase A to lowercase z
[adgk] Find any character in the given set
[^adgk] Find any character outside the given set
(red|blue|green) Find any of the alternatives specified

Metacharacters

Metacharacters are characters with a special meaning:

Metacharacter Description
. Find a single character, except newline or line terminator
\w Find a word character
\W Find a non-word character
\d Find a digit
\D Find a non-digit character
\s Find a whitespace character
\S Find a non-whitespace character
\b Find a match at the beginning/end of a word
\B Find a match not at the beginning/end of a word
\0 Find a NUL character
\n Find a new line character
\f Find a form feed character
\r Find a carriage return character
\t Find a tab character
\v Find a vertical tab character
\xxx Find the character specified by an octal number xxx
\xdd Find the character specified by a hexadecimal number dd
\uxxxx Find the Unicode character specified by a hexadecimal number xxxx

Quantifiers

Quantifier Description
n+ Matches any string that contains at least one n
n* Matches any string that contains zero or more occurrences of n
n? Matches any string that contains zero or one occurrences of n
n{X} Matches any string that contains a sequence of X n's
n{X,Y} Matches any string that contains a sequence of X or Y n's
n{X,} Matches any string that contains a sequence of at least X n's
n$ Matches any string with n at the end of it
^n Matches any string with n at the beginning of it
?=n Matches any string that is followed by a specific string n
?!n Matches any string that is not followed by a specific string n

Properties

Property Description
global Specifies if the "g" modifier is set
ignoreCase Specifies if the "i" modifier is set
lastIndex The index at which to start the next match
multiline Specifies if the "m" modifier is set
source The text of the RegExp pattern

Methods

Method Description
compile() Compiles a regular expression
exec() Tests for a match in a string. Returns the first match
test() Tests for a match in a string. Returns true or false


Content

Android Reference

Java basics

Java Enterprise Edition (EE)

Java Standard Edition (SE)

SQL

HTML

PHP

CSS

Java Script

MYSQL

JQUERY

VBS

REGEX

C

C++

C#

Design patterns

RFC (standard status)

RFC (proposed standard status)

RFC (draft standard status)

RFC (informational status)

RFC (experimental status)

RFC (best current practice status)

RFC (historic status)

RFC (unknown status)

IT dictionary

License.
All information of this service is derived from the free sources and is provided solely in the form of quotations. This service provides information and interfaces solely for the familiarization (not ownership) and under the "as is" condition.
Copyright 2016 © ELTASK.COM. All rights reserved.
Site is optimized for mobile devices.
Downloads: 45 / 158777568. Delta: 0.00335 с