iable">console</span>.<span class="cm-property">log</span>(<span class="cm-variable">a</span>.<span class="cm-property">x</span> <span class="cm-operator">+</span> <span class="cm-variable">a</span>.<span class="cm-property">y</span>); <span class="cm-comment">// &#xC131;&#xACF5;</span>
</code></pre>
<p>&#xD074;&#xB798;&#xC2A4;&#xC640;&#xB3C4; &#xAC19;&#xC774; &#xB3D9;&#xC791;&#xD569;&#xB2C8;&#xB2E4;:</p>
<pre><code class="lang-ts"><span class="cm-keyword">class</span> <span class="cm-variable">Foo</span> {