<h1>列出不同的型態</h1>

<p id='c1'>var check1 = 3.14;</p>
<p id='c2'>var check2 = "true";</p>
<p id='c3'>var check3 = true;</p>
<p id='c4'>var check4;</p>
<p id='c5'>沒定義</p>
<p id='c6'>var check6 = document.getElementsByTagName('p');</p>

<button onclick="togo()">看看情況</button>