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Regular expression to match word pairs joined with colons

I don't know regular expression at all. Can anybody help me with one very simple regular expression which is,

extracting 'word:word' from a sentence. e.g "Java Tutorial Format:Pdf With Location:Tokyo Javascript"? 开发者_开发技巧

  • Little modification: the first 'word' is from a list but second is anything. "word1 in [ABC, FGR, HTY]"
  • guys situation demands a little more modification. The matching form can be "word11:word12 word13 .. " till the next "word21: ... " .

things are becoming complex with sec.....i have to learn reg ex :(

thanks in advance.


You can use the regex:

\w+:\w+

Explanation:
\w - single char which is either a letter(uppercase or lowercase), digit or a _.
\w+ - one or more of above char..basically a word

so \w+:\w+ would match a pair of words separated by a colon.


Try \b(\S+?):(\S+?)\b. Group 1 will capture "Format" and group 2, "Pdf".

A working example:

<html>
<head>
<script type="text/javascript">
function test() {
    var re = /\b(\S+?):(\S+?)\b/g; // without 'g' matches only the first
    var text = "Java Tutorial Format:Pdf With Location:Tokyo  Javascript";

    var match = null;
    while ( (match = re.exec(text)) != null) {
        alert(match[1] + " -- " + match[2]);
    }

}
</script>
</head>
<body onload="test();">

</body>
</html>

A good reference for regexes is https://developer.mozilla.org/en/Core_JavaScript_1.5_Reference/Global_Objects/RegExp


Use this snippet :

 
$str=" this is pavun:kumar hello world bk:systesm" ;
if ( preg_match_all  ( '/(\w+\:\w+)/',$str ,$val ) )
 {
 print_r ( $val ) ;
 }
 else
 {
 print "Not matched \n";
 }


Continuing Jaú's function with your additional requirement:

function test() {
    var words = ['Format', 'Location', 'Size'],
            text = "Java Tutorial Format:Pdf With Location:Tokyo Language:Javascript", 
            match = null;
    var re = new RegExp( '(' + words.join('|') + '):(\\w+)', 'g');
    while ( (match = re.exec(text)) != null) {
        alert(match[1] + " = " + match[2]);
    }
}


I am currently solving that problem in my nodejs app and found that this is, what I guess, suitable for colon-paired wordings:

([\w]+:)("(([^"])*)"|'(([^'])*)'|(([^\s])*))

It also matches quoted value. like a:"b" c:'d e' f:g

Example coding in es6:

const regex = /([\w]+:)("(([^"])*)"|'(([^'])*)'|(([^\s])*))/g;
const str = `category:"live casino" gsp:S1aik-UBnl aa:"b" c:'d e' f:g`;
let m;

while ((m = regex.exec(str)) !== null) {
   // This is necessary to avoid infinite loops with zero-width matches
   if (m.index === regex.lastIndex) {
      regex.lastIndex++;
   }

   // The result can be accessed through the `m`-variable.
   m.forEach((match, groupIndex) => {
      console.log(`Found match, group ${groupIndex}: ${match}`);
   });
}

Example coding in PHP

$re = '/([\w]+:)("(([^"])*)"|\'(([^\'])*)\'|(([^\s])*))/';
$str = 'category:"live casino" gsp:S1aik-UBnl aa:"b" c:\'d e\' f:g';

preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);

// Print the entire match result
var_dump($matches);

You can check/test your regex expressions using this online tool: https://regex101.com

Btw, if not deleted by regex101.com, you can browse that example coding here


here's the non regex way, in your favourite language, split on white spaces, go through the element, check for ":" , print them if found. Eg Python

>>> s="Java Tutorial Format:Pdf With Location:Tokyo Javascript"
>>> for i in s.split():
...     if ":" in i:
...         print i
...
Format:Pdf
Location:Tokyo

You can do further checks to make sure its really "someword:someword" by splitting again on ":" and checking if there are 2 elements in the splitted list. eg

>>> for i in s.split():
...     if ":" in i:
...         a=i.split(":")
...         if len(a) == 2:
...             print i
...
Format:Pdf
Location:Tokyo


([^:]+):(.+)

Meaning: (everything except : one or more times), :, (any character one ore more time)

You'll find good manuals on the net... Maybe it's time for you to learn...

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