 <p>Use "bind()":</p> <pre><code>var contacts = [{firstName: 'Stephen', lastName: 'Hawking'}, {firstName: 'Nicolas', lastName: 'Tesla'}, {firstName: 'Dean', lastName: 'Kamen'} ]; var getFullName = function() { return this.firstName + ' ' + this.lastName; }; for(var i = 0; i &lt; contacts.length; i++){ var contact = contacts[i]; contact.getFullName = getFullName.bind(contact); // Or: //contact['getFullName'] = getFullName.bind(contact); console.log(contact.getFullName()); } </code></pre>