fastest javascript code to change string to title case code example

Example 1: title case javascript

function titleCase(str) {
    return str
        .split(' ')
        .map((word) => word[0].toUpperCase() + word.slice(1).toLowerCase())
        .join(' ');
}
console.log(titleCase("I'm a little tea pot")); // I'm A Little tea Pot

Example 2: snentence case capitalisation js

const string = "tHIS STRING'S CAPITALISATION WILL BE FIXED."
const string = string.charAt(0).toUpperCase() + string.slice(1)