JSFiddle - React, Tailwind, and code Playground

JavaScript

function titleCase(str) {
  return str.toLowerCase().split(" ").map(function(smStr) {
    return smStr.charAt(0).toUpperCase() + smStr.slice(1);
  }).join(" "); 
};

console.log(titleCase('dupa dupa dupa asdasdas dasd asd s'));