c - How does the const keyword affect a pointer that is pointing towards a const variable? -

if consider this:

int *var1; const int *var2 = var1; 

why

*var1 = x;  

compile ,

*var2 = x;  

does not?

in case

 *var2 = x; 

fails compile error message (approx),

error: assignment of read-only location *var2

 *var2 = 10;        ^ 

because have marked value of const qualified.

---

to elaborate, can read statement like

  const int *var2; 

as, declare var2 pointer const int. value pointed var2 constant , cannot changed.

in case want pointer const-qualified, need write like

 int * const var2; 

which declaring var2 const pointer int.

so, later attempt assign var2 produce error, accessing *var2 work fine, value pointed pointer not const-qualified anymore.