A postfix expression followed by an expression in square brackets is a
postfix expression
.One of the expressions shall be a glvalue of type “array of
T” or a prvalue of type “pointer
to
T” and the other shall be a prvalue of unscoped enumeration or integral type
.The result is of type “
T”
.The type “
T” shall be a completely-defined object type
.
The expression
E1[E2] is identical (by definition) to
*((E1)+(E2)),
except that in the case of an array operand, the result is an lvalue
if that operand is an lvalue and an xvalue otherwise
.The expression
E1 is sequenced before the expression
E2.