Sharax:

script type="text/javascript">
var str="abcdefghijkl";
var patt1=/[^d-g]/g;
document.write(str.match(patt1));
/script>





RegExp Object

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.

Syntax

var patt=new RegExp(pattern,modifiers);

or more simply:

var patt=/pattern/modifiers;

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- The [abc] expression is used to find any character between the brackets.
- The [^abc] expression is used to find any character not between the brackets.


NB:
A whitespace character can be:

•A space character
•A tab character
•A carriage return character
•A new line character
•A vertical tab character
•A form feed character

----
var patt1=new RegExp("e"); // means 'e' ma ku jirtaa?

document.write(patt1.test("The best things in life are free"));

----


•pattern specifies the pattern of an expression
•modifiers specify if a search should be global, case-sensitive, etc.
For a tutorial about the RegExp object, read our JavaScript RegExp Object tutorial.


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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 = var str="That's hot!"; var patt1=/h.t/g;
\w Find a word character = var str="Give 100%!"; var patt1=/\w/g;
\W Find a non-word character  = var str="Give 100%!"; var patt1=/\W/g;
\d Find a digit   = var str="Give 100%!"; var patt1=/\d/g;
\D Find a non-digit character = var str="Give 100%!"; var patt1=/\D/g;
\s Find a whitespace character = var str="Is this all there is?"; var patt1=/\s/g;
\S Find a non-whitespace character = var str="Is this all there is?"; var patt1=/\S/g;
\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 to 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 

RegExp Object 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 

RegExp Object 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