Question

For example suppose I always have a string that is delimited by “-“. Is there a way to transform

it-is-a-great-day-today

to

itIsAGreatDayToday

Using RegEx?

Answer 1

Yes (edited to support non-lowercase input and Unicode):

function camelCase(input) { 
    return input.toLowerCase().replace(/-(.)/g, function(match, group1) {
        return group1.toUpperCase();
    });
}

See more about “replace callbacks” on MDN’s “Specifying a function as a parameter” documentation.

The first argument to the callback function is the full match, and subsequent arguments are the parenthesized groups in the regex (in this case, the character after the the hyphen).