Responding to Events
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>html</span><span class="token punctuation">></span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>head</span><span class="token punctuation">></span></span><span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>head</span><span class="token punctuation">></span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>body</span><span class="token punctuation">></span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>h1</span> <span class="token attr-name">id</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span>heading<span class="token punctuation">"</span></span><span class="token punctuation">></span></span>Boring heading<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>h1</span><span class="token punctuation">></span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>button</span> <span class="token special-attr"><span class="token attr-name">onclick</span><span class="token attr-value"><span class="token punctuation attr-equals">=</span><span class="token punctuation">"</span><span class="token value javascript language-javascript"><span class="token function">changeColor</span><span class="token punctuation">(</span><span class="token punctuation">)</span></span><span class="token punctuation">"</span></span></span><span class="token punctuation">></span></span>Shazam<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>button</span><span class="token punctuation">></span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>script</span><span class="token punctuation">></span></span><span class="token script"><span class="token language-javascript">
            <span class="token keyword">const</span> heading <span class="token operator">=</span> document<span class="token punctuation">.</span><span class="token function">querySelector</span><span class="token punctuation">(</span><span class="token string">"#heading"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
            <span class="token keyword">function</span> <span class="token function">changeColor</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
                heading<span class="token punctuation">.</span>style<span class="token punctuation">.</span>color <span class="token operator">=</span> <span class="token string">"red"</span><span class="token punctuation">;</span>
            <span class="token punctuation">}</span>
        </span></span><span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>script</span><span class="token punctuation">></span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>body</span><span class="token punctuation">></span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>html</span><span class="token punctuation">></span></span>