title: set first box clicked as a default at the first load
body: <p>Im new in reactjs and I create a list of card by mapping in reactjs but I want my first card be clicked as a default at the first load  what can i do for this code.</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
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  <pre class="snippet-code-js lang-js prettyprint-override"><code>&lt;div className="d-flex"&gt;
              {data &amp;&amp; data.length &gt; 0
                ? data.map((item, index) =&gt; {
                    return (
                      &lt;&gt;
                        &lt;div className="box-stock" onClick={() =&gt; selectData(item)}&gt;
                          &lt;div className="top-stock skewed p-5"&gt;
                            &lt;h1&gt;{item.symbol}&lt;/h1&gt;
                            &lt;strong className="text-center"&gt;
                              &lt;span&gt; (0.25)&lt;/span&gt;
                              {item.stockNum}
                            &lt;/strong&gt;
                            &lt;Label className="text-center"&gt;
                              EPS:&lt;span className="text-white"&gt;{item.EPS}&lt;/span&gt;
                            &lt;/Label&gt;
                            &lt;Label className="text-center"&gt;
                              P/E:&lt;span className="text-white"&gt;{item.PE}&lt;/span&gt;
                            &lt;/Label&gt;
                          &lt;/div&gt;
                        &lt;/div&gt;
                      &lt;/&gt;
                    );
                  })
                : 'no data'}
            &lt;/div&gt;</code></pre>
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