Why is it legal to do aray+i (i is any integer) but not aray++

Question

Lets say that aray is an array .We can do basic arithmetic functions like addition (+) and substraction(-) on that aray but using --/++ gives an erroes thats says that lvalue is required as ++/-- operand.GIven that array is like a pointer using aray+3,shouldn't it point to the 4the element of the array but its seems that it still points to the first element....Any clue anyone...:(

Answer 1

Name of array is a pointer to its first element. So if you do operation like arr+1 you just add 1 to its address hence you get second element. But when you do something like arr++ you basicly say (arr=arr+1) that you wanna override whole array with its second element, and that is illegal.

Answer 2

I was hoping to give you a quick hint on lvalues but it turns out in c++ it's a little more involved (like whether "l" means "left" or object "locator" expression; it's changed over time). I'm linking this just in case you want a little more insight on the error message itself:
http://en.cppreference.com/w/cpp/language/value_category

Answer 3

0_o how did i miss that...srsly thanks for that ;)