JSFiddle - React, Tailwind, and code Playground

JavaScript

var a = "who all are coming to the party and merry around in florida";

res = ""; resarr = [];

for(i=0 ;i<a.length; i++) {
    
    if(a[i] == " ") {
        res+= resarr.reverse().join("")+" ";
        resarr = [];
    }
    else {
        resarr.push(a[i]);
    }   
}
console.log(res);