title: How to convert a char array to a byte array?
body: <p>I'm working on my project and now I'm stuck with a problem that is, how can I convert a char array to a byte array?.</p>
  
  <p>For example: I need to convert <code>char[9]</code> <code>"fff2bdf1"</code> to a byte array that is <code>byte[4]</code> is <code>0xff,0xf2,0xbd,0xf1</code>.</p>