Is it possible to use Regex to make the first of each word Capital, and replace underscores with spaces?

Question

I can do each of them using regex, but I'm unsure how to combine them into a single regex to achieve both.

For example, this is what I'd like to happen:

HELLO_THERE -> Hello There

Found this, but it does the opposite of what I want, it lowercases the first, when i'd like it to lower case everything AFTER the first:

function changeStr(string){
  return string.replace(/(?:_| |\b)(\w)/g, function($1){return $1.toLowerCase().replace('_',' ');});
}

changeStr(HELLO_THERE) -> hELLO tHERE

In Javascript, not natively no. In other flavors see https://stackoverflow.com/a/1159389/2191572 — MonkeyZeus, Apr 08 '21 at 16:41
Jav use TWO SEPARATE regexes. its not possible to "comnbine" — Fattie, Apr 08 '21 at 16:45
@Fattie It's never too late to learn something [new](https://stackoverflow.com/a/67008486/2191572) — MonkeyZeus, Apr 08 '21 at 16:58
@Fattie If you'd like to see that solved specifically then feel free to ask a new question. OP has not allured to the possibility of your example. — MonkeyZeus, Apr 08 '21 at 19:11

MonkeyZeus · Accepted Answer · 2021-04-08T16:56:24.113

Not in a single regex, no. But you can make use of an anonymous function for the replacement:

function changeStr( string ){
   
    // Match underscores or the alphabet
    return string.replace(/[A-Za-z]+|_/g, function( match ){
        if( match === '_' ){
            // If we have an underscore then return a space
           return ' ';
        }
        else{
            // For everything else we capitalize the first char and lowercase the rest
            return match.substr(0, 1).toUpperCase()+match.substr(1).toLowerCase();
        }
    });
}

console.log( changeStr( 'HELLO_THERE_my_frIenD_MonkeyZeus' ) );

Is it possible to use Regex to make the first of each word Capital, and replace underscores with spaces?

1 Answers1