Address-of and Dereference Operators

• The address-of (&) is a symbol used to returns the memory address of a variable or operand.

  int *ptrInt = #
• The address-of (&) is a symbol used to returns the memory address of a variable or operand.

  int *ptrInt = #
• The address-of (&) is a symbol used to returns the memory address of a variable or operand.

  int *ptrInt = #
• The dereference (*) is a symbol used to access the value stored at the memory address held by the pointer.

  *ptrInt = 10;
• The dereference (*) is a symbol used to access the value stored at the memory address held by the pointer.

  *ptrInt = 10;
• int num = 5;

  int *ptrInt = # //address of num will be assign to ptrInt variable

  cout << num << endl; //display the original value of num

  *ptrInt = 10; //use the dereference operator to change the value of the variable num

  cout << num << endl; //display the new value (10) of variable num

  cout << ptrInt << endl; //display the address of variable num

  cout << *ptrInt << endl; //access and display the value (10) of variable num
• int num;

  int *ptrInt; ptrInt = &num; //address of num will be assign to ptrInt variable

  *ptrInt = 5; //use the dereference operator to assign a value to variable num

  cout << num << endl; //display the value of variable num

  cout << ptrInt << endl; //display the address of variable num

  cout << *ptrInt << endl; //access and display the value of variable num
• int num = 5;

  int *ptrInt = &num; //address of num will be assign to ptrInt variable

  int **ptr = &ptrInt; // address of ptrInt will be assign to ptr variable

  cout << num << endl; //display the original value of num

  *ptrInt = 10; //use the dereference operator to change the value of the variable num

  cout << num << endl; //display the new value of variable num

  cout << ptrInt << endl; //display the address of variable num

  cout << *ptrInt << endl; //display the value of variable num
• int *ptrInt = nullptr;

  /*ptrInt variable will be assign a null pointer or no memory address to be assigned */

  *ptrInt = 5; //use the dereference operator to change the value of unknown variable

  cout << ptrInt << endl; //will not display due to error

  cout << *ptrInt << endl; // will not display due to error

  /* This program will be terminated due to SEGMENTATION FAULT, because the program tries to access a memory location that is not allowed to access */
• int *ptrInt = nullptr;

  /*ptrInt variable will be assign a null pointer or no memory address to be assigned */

  *ptrInt = 5; //use the dereference operator to change the value of unknown variable

  cout << ptrInt << endl; //will not display due to error

  cout << *ptrInt << endl; // will not display due to error

  /* This program will be terminated due to SEGMENTATION FAULT, because the program tries to access a memory location that is not allowed to access */
• int *ptrInt = nullptr;

  /*ptrInt variable will be assign a null pointer or no memory address to be assigned */

  *ptrInt = 5; //use the dereference operator to change the value of unknown variable

  cout << ptrInt << endl; //will not display due to error

  cout << *ptrInt << endl; // will not display due to error

  /* This program will be terminated due to SEGMENTATION FAULT, because the program tries to access a memory location that is not allowed to access */