javascript regular expression tutorial

JavaScript RegExp ObjectsOne. RegExp ObjectA regular expression is an object that describes a character pattern.Regular expressions are used to match string patterns and retrieve replacements, and are powerful tools for performing pattern matching on strings.1. Syntax1 var patt=New RegExp (pattern,modifiers); // Mode 1 var patt=/pattern/modifiers; //

About reverse reference Copy codeThe Code is as follows: // test the Function Function matchReg (reg, str ){ Var result = str. match (reg ); If (result ){ Console. dir (result ); } Else { Console. log ('match failed '); } } Var reg =/([A-Za-z] {0, 6}) \ 1 /;Var str = 'andrewandrew ';// Pass the testMatchReg (reg, str ); // Pass (? : Pattern), does not record the content matched by the sub-expression (in this example, Andrew)// Therefore, the referenc

About reverse referenceCopy codeThe Code is as follows:// Test the FunctionFunction matchReg (reg, str ){Var result = str. match (reg );If (result ){Console. dir (result );} Else {Console. log ('match failed ');}}Var reg =/([A-Za-z] {0, 6}) \ 1 /;Var str = 'andrewandrew ';// Pass the testMatchReg (reg, str );// Pass (? : Pattern), does not record the content matched by the sub-expression (in this example, Andrew)// Therefore, the reference to the matc

collection of atomsMatch any character except line break. Any character other than a line break\d matches any decimal number, i.e. [0-9]\d matches any non-decimal number, i.e. [^0-9]\s matches an invisible atom, i.e. [\f\n\r\t\v]\s matches a visible atom, i.e. [^\f\n\r\t\v]\w matches any number, letter, or underscore, i.e. [0-9a-za-z]W: matches any word character that includes an underscore. Similar but not equivalent to "[a-za-z0-9_]", where the "word" character uses the Unicode character set.

This article mainly introduces the UTF-8 regular expression how to match Chinese characters, a small partner can refer to determine whether the input content contains illegal characters, please refer to the following code $ Str = "programming"; // if (! Preg_match ("/^ [\ x {4e00}-\ x {9fa5} A-Za-z0-9 _] + $/u", $ str )) // UTF-8 Chinese characters, letters, numbers, underscores,

I: Indicates case-insensitive when matchingSTR = "JavaScript is different from Java";reg =/java\w*/i;Arr_m = Str.match (reg);//arr_m = ["JavaScript"]G: Indicates a global match is performedSTR = "JavaScript is different from Java";reg =/java\w*/ig;Arr_m = Str.match (reg);//arr_m = ["JavaScript"]M: Indicates that matchi

Recently in reading Requirejs 2.1.15 source code, the source code at the beginning of the definition of a series of variables, there are 4 regular expressions:var commentregexp =/(\/\* ([\s\s]*?) \*\/| ([^:]|^) \/\/(. *) $)/mg, cjsrequireregexp =/[^.] \s*require\s*\ (\s*["'] ([^ '" \s]+) ["']\s*\]/g, jssuffixregexp =/\.js$/, currdirregexp =/^\.\//;Commentregexp is used to match the comments in

Use the exec () method in the Regular Expression of JavaScript This article describes how to use the exec () method in the Regular Expression of JavaScript. It is the basic knowledge of getting started with

JavaScript regular expression characters include two categories:1, ordinary characters .2, escape character .Normal charactersUppercase and lowercase letters, numbers, and any other symbols.Escape character Escape character Meaning \f Page break \ n Line break \ r Carriage return characte

In JavaScript, the regular expression consists of two parts: the matching pattern text of the regular expression, and the modifier that matches the pattern text;Modifier: Modifier Description I Ignore case G Perfor

Paste (alias name): Javascript Regular Expression test webpageHow do you test regular expressions? Write the Code directly in a large segment, wait for the program to run there, and then use alert to display the result? Or is it possible to temporarily write a page and discard it after testing? You can try this page.