Functional vs imperative vs OOP in JavaScript examples

functional.js

function() {
  "use strict";
  var capify = function(str) {
    return [str.charAt(0).toUpperCase(), str.substring(1)].join("");
  };
  var processWords = function(fn, str) {
    return str.split(" ").map(fn).join(" ");
  };
  document.getElementById("main_button").addEventListener("click", function(e) {
    var something = prompt("Give me something to capitalize");
    alert(processWords(capify, something));
  });
}());

imperative.js

var result;
function getText() {
  var someText = prompt("Give me something to capitalize");
  capWords(someText);
  alert(result.join(" "));
};
function capWords(input) {
  var counter;
  var inputArray = input.split(" ");
  var transformed = "";
  result = [];
  for (counter = 0; counter < inputArray.length; counter++) {
    transformed = [
      inputArray[counter].charAt(0).toUpperCase(), 
      inputArray[counter].substring(1)
    ].join("");
    result.push(transformed);
  }
};
document.getElementById("main_button").onclick = getText;

oop.js

(function() {
  "use strict";
  var SomeText = function(text) {
    this.text = text;
  };
  SomeText.prototype.capify = function(str) {
    var firstLetter = str.charAt(0);
    var remainder = str.substring(1);
    return [firstLetter.toUpperCase(), remainder].join("");
  };
  SomeText.prototype.capifyWords = function() {
    var result = [];
    var textArray = this.text.split(" ");
    for (var counter = 0; counter < textArray.length; counter++) {
      result.push(this.capify(textArray[counter]));
    }
    return result.join(" ");
  };

  document.getElementById("main_button").addEventListener("click", function(e) {
    var something = prompt("Give me something to capitalize");
    var newText = new SomeText(something);
    alert(newText.capifyWords());
  });
}());