title: Confused with a statement
body: <p>I want to check if the 4th byte of my array is equal to any of these : 0xe0 0xe1 0xe2 0xe3 0xe4 0xe5 0xe6 0xe7 0xe8 0xe9 0xeA 0xeB 0xeC 0xeD 0xeE 0xeF.
  My friend told me to use the statement (array[3] &amp; 0xf0) == 0xe0.
  This works but i can't actually understand why.</p>