switch... case 0, 2, 4, 6, 8:

[westfw]

if (c & 1) {
   // c is odd
} else {
  // c is even
}

Or perhaps:

if (c >= 0) && (c <=9) {
  if (c % 2) {
    // c is even
  } else {
    // c is odd
  }
}