Attempting to modify a constant pointer to constant data. - C++ Data Type

Description

Attempting to modify a constant pointer to constant data.

Demo Code

#include <iostream> 
using namespace std; 

int main() //from  w w  w . j ava  2s.  c om
{ 
    int x = 5, y; 

    // ptr is a constant pointer to a constant integer. 
    // ptr always points to the same location; the integer at that location cannot be modified. 
    const int *const ptr = &x; 

    cout << *ptr << endl; 

    //*ptr = 7; // error: *ptr is const; cannot assign new value 
    //ptr = &y; // error: ptr is const; cannot assign new address 
}

Result

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Related Tutorials

• Passing a const Pointer
• Ensuring That a Function Doesn't Modify an Argument
• Using a properly initialized constant variable.
• Attempting to modify a constant pointer to nonconstant data.
• Attempting to modify data through a nonconstant pointer to constant data.