<span class="token operator">&lt;</span><span class="token operator">!</span><span class="token constant">DOCTYPE</span> html<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>html<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>head<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>script<span class="token operator">&gt;</span>
<span class="token keyword">function</span> <span class="token function">myFunction</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
  document<span class="token punctuation">.</span><span class="token function">getElementById</span><span class="token punctuation">(</span><span class="token string">"demo"</span><span class="token punctuation">)</span><span class="token punctuation">.</span>innerHTML <span class="token operator">=</span> <span class="token string">"Paragraph changed."</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token operator">&lt;</span><span class="token operator">/</span>script<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span><span class="token operator">/</span>head<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>body<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>h2<span class="token operator">&gt;</span>JavaScript <span class="token keyword">in</span> Head<span class="token operator">&lt;</span><span class="token operator">/</span>h2<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>p id<span class="token operator">=</span><span class="token string">"demo"</span><span class="token operator">&gt;</span><span class="token constant">A</span> Paragraph<span class="token punctuation">.</span><span class="token operator">&lt;</span><span class="token operator">/</span>p<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>button type<span class="token operator">=</span><span class="token string">"button"</span> onclick<span class="token operator">=</span><span class="token string">"myFunction()"</span><span class="token operator">&gt;</span>Try it<span class="token operator">&lt;</span><span class="token operator">/</span>button<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span><span class="token operator">/</span>body<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span><span class="token operator">/</span>html<span class="token operator">&gt;</span> 

<span class="token operator">&lt;</span><span class="token operator">!</span><span class="token constant">DOCTYPE</span> html<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>html<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>body<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>h2<span class="token operator">&gt;</span>JavaScript <span class="token keyword">in</span> Body<span class="token operator">&lt;</span><span class="token operator">/</span>h2<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>p id<span class="token operator">=</span><span class="token string">"demo"</span><span class="token operator">&gt;</span><span class="token constant">A</span> Paragraph<span class="token punctuation">.</span><span class="token operator">&lt;</span><span class="token operator">/</span>p<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>button type<span class="token operator">=</span><span class="token string">"button"</span> onclick<span class="token operator">=</span><span class="token string">"myFunction()"</span><span class="token operator">&gt;</span>Try it<span class="token operator">&lt;</span><span class="token operator">/</span>button<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>script<span class="token operator">&gt;</span>
<span class="token keyword">function</span> <span class="token function">myFunction</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
  document<span class="token punctuation">.</span><span class="token function">getElementById</span><span class="token punctuation">(</span><span class="token string">"demo"</span><span class="token punctuation">)</span><span class="token punctuation">.</span>innerHTML <span class="token operator">=</span> <span class="token string">"Paragraph changed."</span><span class="token punctuation">;</span>
<span class="token punctuation">}</span>
<span class="token operator">&lt;</span><span class="token operator">/</span>script<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span><span class="token operator">/</span>body<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span><span class="token operator">/</span>html<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span><span class="token operator">!</span><span class="token constant">DOCTYPE</span> html<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>html<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>body<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>h2<span class="token operator">&gt;</span>External JavaScript<span class="token operator">&lt;</span><span class="token operator">/</span>h2<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>p id<span class="token operator">=</span><span class="token string">"demo"</span><span class="token operator">&gt;</span><span class="token constant">A</span> Paragraph<span class="token punctuation">.</span><span class="token operator">&lt;</span><span class="token operator">/</span>p<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>button type<span class="token operator">=</span><span class="token string">"button"</span> onclick<span class="token operator">=</span><span class="token string">"myFunction()"</span><span class="token operator">&gt;</span>Try it<span class="token operator">&lt;</span><span class="token operator">/</span>button<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>p<span class="token operator">&gt;</span><span class="token punctuation">(</span>myFunction is stored <span class="token keyword">in</span> an external file called <span class="token string">"myScript.js"</span><span class="token punctuation">)</span><span class="token operator">&lt;</span><span class="token operator">/</span>p<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>script src<span class="token operator">=</span><span class="token string">"https://www.w3schools.com/js/myScript.js"</span><span class="token operator">&gt;</span>
<span class="token comment">/* yourpathtofile/filename.js */</span> <span class="token operator">&lt;</span><span class="token operator">/</span>script<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span><span class="token operator">/</span>body<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span><span class="token operator">/</span>html<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span><span class="token operator">!</span><span class="token constant">DOCTYPE</span> html<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>html<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span>body<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>h2<span class="token operator">&gt;</span>External JavaScript<span class="token operator">&lt;</span><span class="token operator">/</span>h2<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>p id<span class="token operator">=</span><span class="token string">"demo"</span><span class="token operator">&gt;</span><span class="token constant">A</span> Paragraph<span class="token punctuation">.</span><span class="token operator">&lt;</span><span class="token operator">/</span>p<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>button type<span class="token operator">=</span><span class="token string">"button"</span> onclick<span class="token operator">=</span><span class="token string">"myFunction()"</span><span class="token operator">&gt;</span>Try it<span class="token operator">&lt;</span><span class="token operator">/</span>button<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>p<span class="token operator">&gt;</span><span class="token punctuation">(</span>myFunction is stored <span class="token keyword">in</span> an external file called <span class="token string">"myScript.js"</span><span class="token punctuation">)</span><span class="token operator">&lt;</span><span class="token operator">/</span>p<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span>script src<span class="token operator">=</span><span class="token string">"https://www.w3schools.com/js/myScript.js"</span><span class="token operator">&gt;</span><span class="token operator">&lt;</span><span class="token operator">/</span>script<span class="token operator">&gt;</span>

<span class="token operator">&lt;</span><span class="token operator">/</span>body<span class="token operator">&gt;</span>
<span class="token operator">&lt;</span><span class="token operator">/</span>html<span class="token operator">&gt;</span>