X value is constant 5 , and z denote the address of x value . But we don't know address of x value.it show error output why ?

Question

int*z;
int const x= 5;
z=&x;
z++;
cout<<z;

Answer 1

You have defined value of x constant and after that you created reference variable which is z=&x ; first read the concept of reference if you change the value of z then x will automatically change and you cannot change the value of constant variable so its error.

Answer 2

int* cannot point to const int. You need to declare const pointer e.g. int const* z.