javascript regular expression tutorial

This article mainly introduces how to replace the image address (imgsrc) in a string with a JavaScript Regular Expression, and analyzes common tips and precautions for JS Regular Expression replacement in combination with examples, for more information about how to replace t

JavaScript regular expressions have 3 modifiers of/I,/m, and/g. /I is the most common, and best understood, case-insensitive representation of regular expression matches.var regex =/abc/i;alert (Regex.test ("abc"));//true/ m stands for multiline mode multiline, if the target string does not contain a newline character

what is a regular expression (Regular expreSSion)A regular expression is an object that describes the character pattern.Can handle more complex strings　　Regular Expressions in

Wys: how to use only the regular syntax supported by JavaScript Copy codeThe Code is as follows: ThoughtsOne of the difficulties of this problem lies in the limited regular expression features supported by JavaScript. The author has come up with a non-

}) is not greedy. The non-Greedy mode matches as few searched strings as possible, while the default greedy mode matches as many searched strings as possible. (? : Pattern) matches pattern but does not get the matching result. That is to say, this is a non-get match and is not stored for future use. You can view the. Source attribute of the regular expression object by checking whether the

1. The most important three symbols in regular expressions:1.1 BIn regular expressions, B has 3 types of parentheses:1.1.1 square brackets "[".The square brackets "[" are the characters that need to be matched. Bracketed content only matches one single character.^[ab]$1.1.2 Curly Brace "{"The curly brace "{" is the number of matching characters specified.^[ab]{3}$1.1.3 Parenthesis "("The parentheses "(" are

Regular expressions are long-standing, and the Find-and-replace feature is very powerful, but templates are difficult to remember. The 2 methods of the match (), replace () of the string object in JavaScript use a regular expression template. When the template content does not match the string, match () returns Null,re

general situation is greedyAbout the results returned by the RegExp object exec functionCopy the code code as follows:What is the result of the return?Console.dir (Result) in the Matchreg function can explain the problem, FirebugAbout the Replace function of stringfunction Camelize (str) {Return Str.replace (/-(\w)/g, function (Inputstr, p1) {Console.log (p1);return P1.touppercase ();});}Console.log (camelize (' Background-color '));function Uncamelize (str, SEP) {Sep = Sep | | ‘-‘;Return Str.r

] that converts a character A or B or C to a class, and the expression can match such characters.Using the metacharacters ^ to create a negative or inverse class, the reverse class means something that is not part of a class, such as: an expression [^ABC] represents something that is not a character A or B or C.Use metacharacters-Create scope classes such as: [A-z] to concatenate two characters representing

Javascript Regular Expression usage:Copy codeThe Code is as follows:Function checkreg (myreg, mytext){If (myreg. test (mytext){Alert ("OK ");Return true;}Else{Return false;}}// ANOTHER METHODCopy codeThe Code is as follows:Function checkreg (myreg, mytext){Var pattern = myreg; // or var pattern = new RegExp (myreg, "gi ");If (pattern. test (mytext )){Alert ("OK "

Wys: how to use only the regular syntax supported by JavaScriptCopy codeThe Code is as follows: ThoughtsOne of the difficulties of this problem lies in the limited regular expression features supported by JavaScript. The author has come up with a non-JavaScript solution, as

Regular expressions are detailed. Regular expressions in PHP (1) PHP inherits the consistent tradition of * NIX and fully supports the processing of regular expressions. Regular expressions provide an advanced, but not intuitive string matching and processing of regular expr