A+ 1 indicates that the offset is sizeof(a[0]) units.

This is mainly a and&; A represents the address of the first element in the array, that is, the address of a[0].

And&A represents the address of the whole array, which makes it difficult for&; If a is added with 1, the compiler will automatically recognize that a is an array, get the size of a (sizoef(a)), and then move to the back of the whole array.