Comment by jbandela1

If you want some nice examples of how undefined behavior results in weirdness, see https://devblogs.microsoft.com/oldnewthing/20140627-00/?p=63...

An interesting example from there is how the compiler can turn

    int table[4];
    bool exists_in_table(int v)
    {
        for (int i = 0; i <= 4; i++) {
            if (table[i] == v) return true;
        }
        return false;
    }

Into:

    bool exists_in_table(int v)
    {
        return true;
    }