Regular formula (ii)

Continue to share in the previous chapter.

/* Use the grouping pattern to match */var pattern =/8 (. *) 8/;//get 8. Any character between 8 var str = ' Goo8gle8 '; Str.match (pattern); alert (regexp.$1);//gle, get the string contents of the first grouping var pattern =/8 (. *) 8/;//get 8. Any character between 8 var str = ' Goo8gle8 '; var result =str.replace (pattern, ' <strong>$1</strong> ');// Gets the replacement string output document.write (result);

Run Results :

var pattern =/(. *) \s (. *)/;var str = ' Google Baidu '; var result =str.replace (Pattern, ' $ $ $ ');//replace two grouped values with output document.write (result);

Run Results :

Greed and inertia

/* About greed and inertia */var pattern =/[a-z]+?/;//? Closed greedy match, only replaced by a var str = ' Abcdefjh '; var result =str.replace (pattern, ' xxx '); alert ( result);

Run Results :

Varpattern =/8 (. +?) 8/;/ /Prohibit greedy, open global (another forbidden greedy/8 ([^8]*) 8/) var str = ' A8b8c8d8e8fjh '; var result =str.replace (pattern, ' <strong>$1</ Strong> ');d ocument.write (result);

Run Results :

/* Use EXEC to return array */var pattern =/^[a-z]+\s[0-9]{4}$/i;//beginning to end of line match var str = ' Google + '; alert (pattern.exec (str));//Return entire string var pattern =/^[a-z]+/i;//only matches the letter var str = ' Google + '; alert (pattern.exec (str));//returns Google var pattern =/^ ([a-z]+) \s ([ 0-9]{4}) $/i;//use the grouping var str = ' Google + '; alert (pattern.exec (str) [0]);//Return Google2015alert (Pattern.exec (str) [1]);// Returns Googlealert (Pattern.exec (str) [2]);//returns 2015//capture grouping and non-capturing grouping */var pattern =/(\d+) ([a-z]+)/;//capturing grouping var str = ' 2015google '; alert (pattern.exec (str));

Run Results :

var pattern =/(\d+) (?: [A-z])/;//non-capturing grouping var str = ' 2015google '; alert (pattern.exec (str));

Run Results :

/* Use Group nesting */var pattern =/(A? ( B? (C?))) /;//from outside to get var str = ' ABC '; alert (pattern.exec (str));

Run Results :

/* Use forward capture */var pattern =/(goo (? =gle))/;//goo must follow gle to capture var str = ' Google '; alert (pattern.exec (str));//goo,goo/* Use special characters to match */var pattern =/\.\[\/b\]/;//special characters, escaped with \ symbol var str = '. [/b] '; Alert (pattern.exec (str));//. [/b]/* Use newline mode */var pattern =/^\d+/mg;//enable line break mode var str = ' 1.baidu\n2.google\n3.bing '; var result =str.replace (pattern, ' # ' //1/2/3 with ' # ' to replace alert (result);

Run Results :

Common regular

/* Check ZIP code */var pattern =/[1-9][0-9]{5}/;//a total of 6 digits, the first digit cannot be 0var str = ' 165000 '; alert (Pattern.test (str));//true/* Check file Compression Package */ var pattern =/[\w]+\.zip|rar|gz/;//\w All numbers and letters and _var str = ' 123.gz '; alert (Pattern.test (str));//true/* Delete extra spaces */var pattern =/\s/g;var str = ' 1 2 3 '; var result =str.replace (pattern, '), alert (result),//123/* Delete the leading and trailing spaces */var pattern =/^\s+/g;/ /Force first var str = '    1 2 3   '; var result =str.replace (pattern, ');p attern =/\s+$/;//Force tail result =result.replace (pattern , '); Alert (' | ') + result+ ' | '); /123

Run Results ( Mandatory first / mandatory tail ):

/* Simple Email Verification */var pattern =/^ ([a-za-z0-9_\.] +) @ ([a-za-z0-9_\.] +)\. ([a-za-z]{2,4})/;var str = ' [email protected] '; Alert (Pattern.test (str));//true

Regular formula (ii)