Question related to the delete oprerator for a pointer

Question

int *ptr=new int;
*ptr=10;
delete ptr;
cout<<*ptr;

still printing 10 as the output after i had freed the memory which has stored the value 10. i dont understand why?

Answer 1

Memory keeps the same values till it’s overwritten. The delete operator just frees the memory, it does not overwrite the memory. After deleting a pointer, dereferencing it is undefined behavior.