Special characters in regular expressions
Character implication
\ As a turn, that is, the characters usually after "\" are not interpreted in the original sense, such as the/b/matching character "B", when B is preceded by a backslash/\b/, to
The checksum is all made up of numbers
Funtin Isigit (s) {var patrn=/^[0-9]{1,20}$/; if (!patrn.x (s)) Rturn Fals Rturn Tru}
Javasript Form validation mail to determine whether an input is mailbox mail and implemented through regular expressions.
Replace () is a simple replacement of characters.
ExampleCodeAs follows:
It only replaces the first letter. However, if you add a regular expression, the results will be different! Replace () supports regular expressions. It can match
The regular expression of JSWhether the checksum is all made up of numbersCodefunction IsDigit (s){var patrn=/^[0-9]{1,20}$/;if (!patrn.exec (s)) return falsereturn True}Check login name: Only 5-20 entries begin with a letter, can be numbered, "_", "
// Check whether it is composed of digits[Code] function isDigit (s) {var patrn =/^ [0-9] {1, 20} $/; if(! Patrn.exe c (s) return false return true} [/code]
// Check Logon Name: You can enter only 5-20 strings starting with a letter, which can
1 overview
A regular expression (Regular Expression) is a matching pattern that describes the characteristics of a string of text.
Just as the words "tall" and "strong" in natural language are abstracted out to describe things, regular expressions
JavaScript's RegExp objects and string objects define methods that use regular expressions to perform powerful pattern matching and text retrieval and substitution functions.
In JavaScript, regular expressions are represented by a RegExp object. Of
Regular
Regular expression is regular expression, it seems that English is better than Chinese understand more, is to check expression characters do not conform to the rules!! Regular expressions have a very powerful and complex object regexp,
Http://www.jb51.net/article/25313.htmRegular expressions can:• Test a pattern for a string. For example, you can test an input string to see if there is a phone number pattern or a credit card number pattern in the string. This is called data
The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion;
products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the
content of the page makes you feel confusing, please write us an email, we will handle the problem
within 5 days after receiving your email.
If you find any instances of plagiarism from the community, please send an email to:
info-contact@alibabacloud.com
and provide relevant evidence. A staff member will contact you within 5 working days.