Return the provided string with the first letter of each word capitalized. Make sure the rest of the word is in lower case.

[akmalist]

String.prototype.replaceAt = function(index, character) {
    return this.substr(0, index) + character + this.substr(index+character.length);
};

function titleCase(str) {
    var newTitle = str.split(' ');
    var updatedTitle = [];
    for (var st in newTitle) {
        updatedTitle[st] = newTitle[st].toLowerCase().replaceAt(0, newTitle[st].charAt(0).toUpperCase());
    }
    return updatedTitle.join(' ');
}

titleCase("I'm a little tea pot");

[akmalist]

function titleCase(str) {
  return str.toLowerCase().replace(/(^|\s)\S/g, (L) => L.toUpperCase());
}

[akmalist]

function titleCase(str) {
  var convertToArray = str.toLowerCase().split(" ");
  var result = convertToArray.map(function(val){
      return val.replace(val.charAt(0), val.charAt(0).toUpperCase());
  });
  return result.join(" ");
}

titleCase("I'm a little tea pot");

Code Explanation: We are making entire string lowercase and then converting it into array. Then we are using map function to replace the lowercase character with uppercase. Finally, we are returning the string using join method.