CODEWITHSUNDEEP
javascriptregex
GV3
GV3

Reputation: 491

Regex of every first char and any capital in the word

I'm having troubles with REGEX trying to build one that would retrieve the first letter of a word and any other Capital letter of that word and each first letter including the any Capital letter in the same word

"WelcomeBack to NorthAmerica a great place to be" = WBTNAAGPTB
"WelcomeBackAgain to NorthAmerica it's nice here" = WBATNAINH
"Welcome to the NFL, RedSkins-Dolphins play today" = WTTNFLRSDPT

tried this juus to get the first 2 matches: 

/([A-Z])|\b([a-zA-Z])/g

Any help is welcomed, thanks

Upvotes: 2

Views: 223

Answers (4)

Mustofa Rizwan
Mustofa Rizwan

Reputation: 10476

You can try this, it will also take care of whitespaces 

str = str.match(/([A-Z])|(^|\s)(\w)/g);
str = str.join('');
str=str.replace(/ /g,'');
return str.toUpperCase();

Upvotes: 1

Shekhar Khairnar
Shekhar Khairnar

Reputation: 2691

You can use regex as : /\b[a-z]|[A-Z]+/g;

<html>
   <head>
      <title>JavaScript String match() Method</title>
   </head>
   <body>
      <script type="text/javascript">
         var str = "WelcomeBack to NorthAmerica a great place to be";
         var re = /\b[a-z]|[A-Z]+/g;
         var found = str.match( re );
         found.forEach(function(item, index) {
            found[index] = item.toUpperCase();
        });
          document.write(found.join('')); 
      </script>
      
   </body>
</html>

Upvotes: 1

HumanCatfood
HumanCatfood

Reputation: 1001

Try this:

let s = "WelcomeBack to NorthAmerica a great place to be";
s = s.match(/([A-Z])|(^|\s)(\w)/g);    // -> ["W","B"," t", " N"...]
s = s.join('');                        // -> 'WB t N...'
s = s.replace(/\s/g, '');              // -> 'WBtN...'
return s.toUpperCase();                // -> 'WBT ...'

/(?:([A-Z])|\b(\w))/g matches every uppercase letter ([A-Z]) OR | every letter (\w) that follows the start of the string ^ or a whitespace \s.

(I couldn't get the whitespace to not be captured for some reason, hence the replace step. Surely there are better tricks, but this is the most readable I find.)

Upvotes: 1

Wiktor Stribiżew
Wiktor Stribiżew

Reputation: 627419

You need a regex that will match all uppercase letters and those lowercase letters that appear at the start of the string or after a whitespace:

var re = /[A-Z]+|(?:^|\s)([a-z])/g; 
var strs = ["WelcomeBack to NorthAmerica a great place to be", "WelcomeBackAgain to NorthAmerica it's nice here", "Welcome to the NFL, RedSkins-Dolphins play today"];
for (var s of strs) {
  var res = "";
  while((m = re.exec(s)) !== null) {
    if (m[1]) {
       res += m[1].toUpperCase();
    } else {
      res += m[0];
    }
  }
  console.log(res);
}

Here, [A-Z]+|(^|\s)([a-z]) matches multiple occurrences of:

  • [A-Z]+ - 1 or more uppercase ASCII letters
  • | - or
  • (?:^|\s) - start of string (^) or a whitespace (\s)
  • ([a-z]) - Group 1: one lowercase ASCII letter.

Upvotes: 3

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