$ is not defined error? code example

Example 1: $ is not defined

<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js" type="text/javascript"></script>

Example 2: Uncaught ReferenceError: $ is not defined

<script src="https://code.jquery.com/jquery-1.9.1.js"></script>
<script src="path-para-seu-script"></script>