http://www.freecodecamp.com/nirajkrz 's solution for Bonfire: Search and Replace

bonfire-search-and-replace.js

// Bonfire: Search and Replace
// Author: @nirajkrz
// Challenge: http://www.freecodecamp.com/challenges/bonfire-search-and-replace
// Learn to Code at Free Code Camp (www.freecodecamp.com)

function myReplace(str, before, after) {
  // Find index where before is on string
  var index = str.indexOf(before);
  // Check to see if the first letter is uppercase or not
  if (str[index] === str[index].toUpperCase()) {
    // Change the after word to be capitalized before we use it.
    after = after.charAt(0).toUpperCase() + after.slice(1);
  }
  // Now replace the original str with the edited one.
  str = str.replace(before, after);

  return str;
}

myReplace("A quick brown fox jumped over the lazy dog", "jumped", "leaped");