Contents

Section 14.1 Basic Concepts

Section 14.2 Input and Output Operators

Section 14.3 Arithmetic and Relational Operators

Section 14.4 Assignment Operators

Section 14.5 Subscript Operator

Section 14.6 Increment and Decrement Operators

Section 14.7 Member Access Operators

Section 14.8 Function-Call Operator

Section 14.9 Overloading, Conversions, and Operators

Chapter Summary

Defined Terms

In Chapter 4, we saw that C++ defines a large number of operators and automatic conversions among the built-in types. These facilities allow programmers to write a rich set of mixed-type expressions.

C++ lets us define what the operators mean when applied to objects of class type. It also lets us define conversions for class types. Class-type conversions are used like the built-in conversions to implicitly convert an object of one type to another type when needed.

Operator overloading lets us define the meaning of an operator when applied to operand(s) of a class type. Judicious use of operator overloading can make our programs easier to write and easier to read. As an example, because our original Sales_item class type (§ 1.5.1, p. 20) defined the input, output, and addition operators, we can print the sum of two Sales_items as

cout << item1 + item2;  // print the sum of two Sales_items

In contrast, because our Sales_data class (§ 7.1, p. 254) does not yet have overloaded operators, code to print their sum is more verbose and, hence, less clear:

print(cout, add(data1, data2));  // print the sum of two Sales_datas