Array and pointer of C ++

Array Definition

The dimension of the array must be defined by a constant expression greater than or equal to 1. This constant expression can only contain an integer nominal value constant, an enumeration constant, or an integer const object initialized using a constant expression.

Non-const variables and the const variables whose values are not known at the runtime cannot be used to define the dimension of the array.

Const   Int Size = Get_size ();
Int A_size =   26 ;
Int Table [size]; // Error
Int Array [a_size]; // Error

//Although the size is a const int constant, the value cannot be obtained in the compilation phase. A_size is an integer variable, and its value may be changed during runtime. Therefore, the size of the array must be determined at runtime, so it is invalid.