can i use a[-1] to refer to the last member?

[CharChen]

can i use a[-1] to refer to the last member?
i am just used to this ..
however..i got something odd..

int t=432;
int a[4];
printf("%d",a[-1]);// I got 432 

[28poGNh0]

No you can not ,and perhaps you got 432 ,just because you compiler did put the address of "t" aside the address of " a[0]" ,so when you write a[-1] you access the value of "t".

that what I think

[nvrmnd]

that's impossible, did you try to run it again and had the same results?
maybe the compiler assigns random value to each elements of the array and luck put the value of t in the 1st element of the array


a[-1] ??

[Catfish4]

can i use a[-1] to refer to the last member?

No. This is unreliable behavior.

When a function is called, memory is allocated for the function's local variables. This portion of memory is called the "stack".

To my knowledge, the compiler doesn't need to maintain a certain order of local variables on the stack. So your code may not work for other people, and may not work for you either if you enable optimizations.

[ne555]

int& operator[](int index){
   return v[ (index%size+size)%size ];
}