Regex, or regular expressions, are a pattern matching markup that programmers use to search for certain patterns in text. Regular expressions can search for just about anything, depending on how you structure them; they're used all over by programmers because they're invaluable for helping computers sort through data quickly and filter out nonsense that could otherwise cause errors. Regular expressions tend to look scary, especially for non-programmers.
Just look at this: [a-zA-Z0-9_.+-]+@[a-zA-Z0-9_-]+\.[a-zA-Z0-9_.-]+


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Input Your Test String
 

See Output



Learn Rules of Regex


Brackets

Expression Description
[abc] Find any character between the brackets
[^abc] Find any character NOT between the brackets
[0-9] Find any character between the brackets (any digit)
[^0-9] Find any character NOT between the brackets (any non-digit)
(x|y) Find any of the alternatives specified

Metacharacters

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
\udddd Find the Unicode character specified by a hexadecimal number dddd

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
constructor Returns the function that created the RegExp object's prototype
global Checks whether the "g" modifier is set
ignoreCase Checks whether the "i" modifier is set
lastIndex Specifies the index at which to start the next match
multiline Checks whether the "m" modifier is set
source Returns the text of the RegExp pattern

RegExp Object Methods

Method Description
compile() Deprecated in version 1.5. 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
toString() Returns the string value of the regular expression 




References


Term project by Emrah Tema


w3schools regex


lifewire