JS-Modify-&-Delete-Array.html

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    <h1>Modify Array Element</h1>
    <p>Array elements are accessed using their index number:</p>
    <br />
    <p>Array indexes start with 0:</p>
    <p>[0] is the first array element</p>
    <p>[1] is the second</p>
    <p>[2] is the third ...</p>
    <pre
      class="language-markup"
      tabindex="0"
    ><code class="language-markup"><span class="token doctype"><span class="token punctuation">&lt;!</span><span class="token doctype-tag">DOCTYPE</span> <span class="token name">html</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>html</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>head</span><span class="token punctuation">&gt;</span></span>
  <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>title</span><span class="token punctuation">&gt;</span></span>JavaScript<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>title</span><span class="token punctuation">&gt;</span></span>
  <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>script</span><span class="token punctuation">&gt;</span></span><span class="token script"><span class="token language-javascript">
    <span class="token keyword">var</span> a <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token string">"Hamza"</span><span class="token punctuation">,</span><span class="token number">18</span><span class="token punctuation">,</span><span class="token string">"Male"</span><span class="token punctuation">,</span><span class="token string">"BCA"</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
    document<span class="token punctuation">.</span><span class="token function">write</span><span class="token punctuation">(</span>a <span class="token operator">+</span> <span class="token string">"&lt;br&gt;"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    a<span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token string">"Umar"</span><span class="token punctuation">;</span>
    document<span class="token punctuation">.</span><span class="token function">write</span><span class="token punctuation">(</span>a <span class="token operator">+</span> <span class="token string">"&lt;br&gt;"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    a<span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token number">20</span><span class="token punctuation">;</span>
    document<span class="token punctuation">.</span><span class="token function">write</span><span class="token punctuation">(</span>a <span class="token operator">+</span> <span class="token string">"&lt;br&gt;"</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">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>head</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>body</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>body</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>html</span><span class="token punctuation">&gt;</span></span>
</code></pre>
    <h1>Delete Array Element</h1>
    <p>Array elements can be deleted using the JavaScript operator delete.</p>
    <p>Using delete leaves undefined holes in the array.</p>
    <pre
      class="language-markup"
      tabindex="0"
    ><code class="language-markup"><span class="token doctype"><span class="token punctuation">&lt;!</span><span class="token doctype-tag">DOCTYPE</span> <span class="token name">html</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>html</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>head</span><span class="token punctuation">&gt;</span></span>
  <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>title</span><span class="token punctuation">&gt;</span></span>JavaScript<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>title</span><span class="token punctuation">&gt;</span></span>
  <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>script</span><span class="token punctuation">&gt;</span></span><span class="token script"><span class="token language-javascript">
    <span class="token keyword">var</span> a <span class="token operator">=</span> <span class="token punctuation">[</span><span class="token string">"Hamza"</span><span class="token punctuation">,</span><span class="token number">18</span><span class="token punctuation">,</span><span class="token string">"Male"</span><span class="token punctuation">,</span><span class="token string">"BCA"</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
    document<span class="token punctuation">.</span><span class="token function">write</span><span class="token punctuation">(</span>a <span class="token operator">+</span> <span class="token string">"&lt;br&gt;"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    a<span class="token punctuation">[</span><span class="token number">0</span><span class="token punctuation">]</span> <span class="token operator">=</span> <span class="token string">"Umar"</span><span class="token punctuation">;</span>
    document<span class="token punctuation">.</span><span class="token function">write</span><span class="token punctuation">(</span>a <span class="token operator">+</span> <span class="token string">"&lt;br&gt;"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
    <span class="token keyword">delete</span> a<span class="token punctuation">[</span><span class="token number">1</span><span class="token punctuation">]</span><span class="token punctuation">;</span>
    document<span class="token punctuation">.</span><span class="token function">write</span><span class="token punctuation">(</span>a <span class="token operator">+</span> <span class="token string">"&lt;br&gt;"</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">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>head</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>body</span><span class="token punctuation">&gt;</span></span>

<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>body</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>html</span><span class="token punctuation">&gt;</span></span>
</code></pre>
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    a[0] = 10;
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