JSFiddle - React, Tailwind, and code Playground

HTML

With no second param: <span id="cont"></span> <br><br>

With second param: <span id="cont2"></span>

JavaScript

ntohl = function(b, i) {
  return ((0xff & b[i + 0]) << 24) |
         ((0xff & b[i + 1]) << 16) |
         ((0xff & b[i + 2]) << 8) |
         ((0xff & b[i + 3]));
}

bob = [0,0,0,255];


document.getElementById("cont").innerHTML = ntohl(bob); 


document.getElementById("cont2").innerHTML = ntohl(bob,0);