Why can two different enum enumeration-constants have the same integer value?

Question

I know that if I defined an enum weekday like this:

enum weekday {
    MON,
    TUE,
    WED,
    THU,
    FRI,
};

Then, MON would internally e

Answer 1

Just to complement on other answers, I'll give you a practical example of how using the same value for different enumerations on a given enum is widely useful:

enum slots_t {
    SLOT_FIRST = 0,
    SLOT_LEFTARM = SLOT_FIRST,
    SLOT_RIGHTARM = 1,
    SLOT_TORSO = 2,
    SLOT_LEFTLEG = 3,
    SLOT_RIGHTLEG = 4,
    SLOT_LAST = SLOT_RIGHTLEG
};

Then you can do in your code:

for (int i = SLOT_FIRST; i <= SLOT_LAST; ++i) { }