Page 163 - DCAP404 _Object Oriented Programming

Object-oriented Programming Mithilesh Kumar Dubey, Lovely Professional University

Notes Unit 8: Type Conversion

CONTENTS
Objectives
Introduction
8.1 Type Conversions

8.2 Basic Type to Class Type
8.3 Class Type to Basic Type
8.4 Class Type to another Class Type

8.5 Summary
8.6 Keywords
8.7 Review Questions
8.8 Further Readings

Objectives

After studying this unit, you will be able to:

 Recognize the type conversions
 Describe the basic type to class type
 Explain the class type to basic type

 Discuss the class type to another type
Introduction

It is the process of converting one type into another. In other words converting an expression of
a given type into another is called type casting.

A type conversion may either be explicit or implicit, depending on whether it is ordered by the
programmer or by the compiler. Explicit type conversions (casts) are used when a programmer
want to get around the compiler’s typing system; for success in this endeavour, the programmer
must use them correctly. Problems which the compiler avoids may arise, such as if the processor
demands that data of a given type be located at certain addresses or if data is truncated because
a data type does not have the same size as the original type on a given platform. Explicit type
conversions between objects of different types lead, at best, to code that is difficult to read.

8.1 Type Conversions

In a mixed expression constants and variables are of different data types. The assignment
operations cause automatic type conversion between the operand as per certain rules.

The type of data to the right of an assignment operator is automatically converted to the data
type of variable on the left.
Consider the following example:

int x;

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