Page 244 - DCAP404 _Object Oriented Programming

Unit 11: Pointers and Dynamic Memory Management

Address of j = 3276 Notes
Address of k = 7234
Value of j = 6485
Value of k = 3276

Value of i = 3
Value of i = 3
Value of i = 3
Value of i = 3

Task Explain the advantages of pointers to pointers.

11.4 Pointer and Functions

A function is a user defined operation that can be invoked by applying the call operator (“( )”) to
the function’s name. If the function expects to receive arguments, these arguments (actual
arguments) are placed inside the call operator. The arguments are separated by commas. A
functions may be involved in one of the two way;
1. Call by value
2. Call by reference

Call by Value

In this method, the value of each actual argument in the calling function is copied on to the
corresponding formal arguments of the called function. The called function works with and
manipulates its own copy of arguments and because of this, changes made to the formal arguments
in the called function have no effect on the values of the actual arguments in the calling function.

Call by Reference

This method can be used in two ways:
1. By passing the reference
2. By passing the pointer.
A reference is an alias name for a variable.

For instance, the following code
float value = 1700.25;
float &amt = value; //amt reference of value

declares amt as an alias name for the variable value. No separate memory is allocated for amt
rather the variable value can now be accessed by two names value and amt.
value
6009 1700.25
amt

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