title: Unicode escape syntax in Java
body: <p>In Java, I learned that the following syntax can be used for mentioning Unicode characters that are not on the keyboard (eg. non-ASCII characters):</p>
  
  <pre><code>(\u)(u)*(HexDigit)(HexDigit)(HexDigit)(HexDigit)
  </code></pre>
  
  <p>My question is:
  What is the purpose of (u)* in the above syntax?</p>
  
  <p>One use case that I understood which represents Yen symbol in Java is: </p>
  
  <pre><code>char ch = '\u00A5';
  </code></pre>