Bad javascript code - Example for blog post - Remove Unuseful Code

bad.js

function book(name, author, content, date) {
  var name  = name,
    author  = author,
    content = content,
    date    = date;

  var self = { 
    containsWord: function(word) { 
      return content.indexOf(word) >= 0;
    },
    removeWord: function(word) { 
      return self.replaceWord(word, '');
    },
    replaceWord: function(oldWord, newWord) { 
      return content.replace(oldWord, newWord);
    },
    getName: function() { return name; },
    getAuthor: function() { return author; },
    getContent: function() { return content; },
    getDate: function() { return date; }
  };

  return self;
};