title: How can I merge two hashes?
body: <p>I made two hashes <code>hash1</code> and <code>hash2</code> with following keys and values.</p>
  
  <p><strong>Input:</strong></p>
  
  <pre><code>hash1 = {1=&gt;"One", 2=&gt;"Two", 3=&gt;"Three"}
  hash2 = {4=&gt;"First", 5=&gt;"Second", 6=&gt;"Third"}
  </code></pre>
  
  <p><strong>Result:</strong></p>
  
  <p>And I am expecting <code>hash3</code> to give me a result like</p>
  
  <pre><code>hash3 #=&gt; {1 =&gt; "One", 2 =&gt; "Two", 3 =&gt; "Three", 4 =&gt; "First", 5 =&gt; "Second", 6 =&gt; "Third"}
  </code></pre>
  
  <p>Can anyone tell me how I can merge these two hashes? Assume that <code>hash3</code> should contain all keys and all values.</p>