Discussion on: Web Basics: How to Capitalize a Word in JavaScript

[Matteo Rigon]

const capitalize = (str) => {
    return str
        .split('')
        .map((c,i) => i ? c.toLowerCase() : c.toUpperCase())
        .join('')
}

Might be more performant since you have to loop the array anyway

[Samantha Ming]

Woo, I love this solution! Nice use to the falsy value to check the first character (cause 0 is false). Thanks for sharing 💯

[Mihail Malo]

You can just map on the string :v

const capitalize = str =>
  Array.prototype.map
    .call(str, (c, i) => i ? c.toLowerCase() : c.toUpperCase())
    .join('')

But no, it's most likely not going to be performant (even like this), because it involves indexing into every character instead of handing the underlying native string to the native method.

Worse yet, .split('') and such don't play well with composite Unicode graphemes.