When declaring a variable of data type pointer, use the * in front of the variable name. These variables hold a memory location (like B45CDF), not an actual value like 30 or A:
int * Years;
char * Grade;
This tells the program that the value contained in the variable will be a memory address that points to the value at that memory address.
To obtain an actual memory address to use with this variable, the & or reference operator is used.
In the following example, a regular variable is declared. Whenever a variable is declared in a program, the operating system sets aside a memory location in the computer to hold whatever value of a given data type is placed in that memory location. So placing the & in front of a regular variable, tells the operating system that the program wants the memory location address and not the value contained in that memory location.
int * Years;
The following code assigns the memory location for the LoanYears variable to the pointer variable.
Years = &LoanYears;
Note: If the assignment was "Years = LoanYears;" a compiler error would occur since the LoanYears is of the wrong data type that Years. Years only accepts memory locations, not actual values.
To assign a value or change the value of LoanYears using the pointer instead of the actual variable, the following code is used:
*Years = 30;
LoanYears = 30;
NOTE: Among the symbols expected in the code are -> and the use of ++ with the pointer variable for the pointer to the struct.