digit static method
Character.digit(c, 16) — the value of a hex digit, or -1.
Implementation
static int digit(int charCode, int radix) {
int value = -1;
if (charCode >= 0x30 && charCode <= 0x39) value = charCode - 0x30;
if (charCode >= 0x61 && charCode <= 0x7A) value = charCode - 0x61 + 10;
if (charCode >= 0x41 && charCode <= 0x5A) value = charCode - 0x41 + 10;
return value < radix ? value : -1;
}