JSFiddle - React, Tailwind, and code Playground

JavaScript

(function(){
	let testString = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum."
  


  let startDate1 = new Date();
  for(let i = 0 ; i < 1000000; i++){
    let testString2 = testString.replace(/ /g,"-")
  }
  let endDate1 = new Date();
  let dateDiff1 = endDate1 - startDate1
  
  let startDate2 = new Date();
  for(let i = 0 ; i < 1000000; i++){
    let testString2 = testString.split(" ").join("-");
  }
  let endDate2 = new Date();
  let dateDiff2 = endDate2 - startDate2

  
  
  alert(`Using testString.replace(/ /g,"-") time was ${dateDiff1}.
  Using testString.split(" ").join("-"); time was ${dateDiff2}`)
}())