This document discusses type conversion in C++. It explains that type conversion is the process of converting one predefined type into another. It discusses implicit type conversion performed by the compiler without programmer intervention when differing data types are mixed in an expression. It also discusses explicit type conversion using constructor functions and casting operators to convert between basic and class types. Examples are provided of converting between integer, float, and class types.

1. M.Preetha
M.Sc(Information Technology)
NADAR SARASWATHI COLLEGE OF
ARTS &SCIENCE

2. The process of converting one predefined
type into another is called type conversion.
When constants and variable of different
type are mixed in an expression they are
converted the same type.
One type are mixed with variable of
another type.
 The type of the data to the right of an
assignment operator is automatically
converted type of the variable on the left.
Int m;
Float x=3.1419;
M=x;

3. Implicit type conversion
Explicit type conversion

4.  An implicit type conversion is a conversion
Performed by the compiler without programmer
intervention.
 An implicit conversion is applied differing data
type intermixed an expression.
Ch=x; ch and char

5.  If either operand is of type long double other
converted to long double.
 If either operand is float the other converted to
float.
 The either operand is unsigned long other
converted to unsigned long.

6.  The constructor build a string type of object
From a char* type variable a.
 The variable length and p are data member
of the class string.
String::string(char *a)
{
Length=strlen(a);
P=new char[length+1];
Strcpy(p,a);
} c

7. Class time
{
Int hrs;
Int mins;
Public:
……
……
Time (int t) //constructor
{
Hours=t/60; //t in minutes
Mins=t%60;
}
};

8.  The constructor fine a type conversion from
A basic to class type.
 The constructor function do not support
this operation.
 C++ allows overloaded casting operator
used to convert class type data to a basic
type.
Operator type name()
{
.........
………
………
}

9.  Data conversion techniques from a basic to
class type and class to basic type.
Ex:
Objx=objY;//objects of different type
 ObjX is an object of class x and objy is an
object of class y .
Operator typename()

10. #include<iostrteam.h>
#include<conio.h>
Void main()
{
Clrscr();
Float res;
Float f1=15.5,f2=2;
Res=(int)f1/(int)f2;
Cout<<res<<end1;
Res=(int)(f1/f2);
Cout<<res<<end1;
Res=f1/f2;
Cout<<res;
Getch();
}