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  1. #include <iostream>
  2. using namespace std;
  3.  
  4. // Define a simple class
  5. class Student {
  6. public:
  7.     string name;
  8.     int id;
  9.  
  10.     void display() {
  11.         cout << "Name: " << name << ", ID: " << id << endl;
  12.     }
  13. };
  14.  
  15. int main() {
  16.     Student s1;              // create object
  17.     s1.name = "Alice";
  18.     s1.id = 101;
  19.  
  20.     Student* ptr = &s1;      // create pointer to object
  21.  
  22.     // Access members using the arrow operator
  23.      ptr->display();          // prints: Name: Alice, ID: 101
  24.  
  25.     // Modify members using the pointer
  26.  
  27.     ptr->name = "Bob";
  28.     ptr->id = 102;//if this line is comment out this shows id of alice .so this ptr is just reassigning the value
  29.  
  30.     ptr->display();          // prints: Name: Bob, ID: 102
  31.  
  32.     /*if there was another object s2 and ptr was pointing to s2 then first ptr->display will not work.because we didnt set the value;
  33.     it same like int* p=&x;
  34.                  *p=10//would change the value x;
  35.                  this *p is now written as  p-> and as class has many info p->variable(which has to be set )should be written */
  36.  
  37.     return 0;
  38. }
  39.  
Success #stdin #stdout 0s 5320KB
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Standard input is empty
stdout
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Name: Alice, ID: 101
Name: Bob, ID: 102
https://ideone.com/a7sECQ
pointer_use -------VVVI
language:
C++ (gcc 8.3)
created:
17 hours ago
visibility:
public

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