Differences between C language pointer and array A and &a, &a[0], etc

Suppose you define an array int a[5]={1,2,3,4,5};

a It represents this array variable

Here's the thing to remember a Equivalent to &a[0] Are the first element of the array a[0] The address of

and &a It means a The first address of the entire array , Although the actual values of the two are the same, they represent different meanings

a+1 It means The address of the first element plus the length of an element , The length of an element is one int type , That is to say
a+size of(int)

&a+1 Represents the first address of the entire array , Add the length of an array , It is &a+5*size of(int)

Suppose you define a int * Variable of type

int *ptr1 = int *(&a+1)

prt[-1] It is equivalent to *(ptr - 1)