The document discusses various C++ concepts like type conversion, enum types, functions, function arguments, default arguments, recursive functions, function overloading. It provides code examples to demonstrate these concepts like using cast operator for type conversion, defining enum types, defining and calling functions, functions with default arguments, recursive function to calculate sum, overloading functions based on data types.

1. 1. Converting by assignment
operator
2. Using cast operator
Syntax:
(cast_type) expression;
or
cast_type (expression);
09/04/131 VIT - SCSE
Type Conversion
#include<iostream.h>
#include<conio.h>
void main()
{
char ch='A';
int x;
x=(int)ch;
cout<<x;
getch();
}

2. Enum Types
The enum keyword automatically enumerates a list of words
by assigning them values 0,1,2,3,4, and so on.
The general form of enum is:
enum variable_name{ list of constants separated by commas };
e.g:
enum day{sun,mon,tue,wed,thu,fri,sat};
09/04/132 VIT - SCSE

3. # include<iostream.h>
enum day{sun,mon,tue,wed,thu,fri,sat};
void main( )
{
day d1, d2,d3;
d1 = mon;
d2 = fri;
int diff = d2 – d1;
cout<<"days between = "<<diff<<endl;
if(d1<d2)
cout<< "day1 comes before day2n";
}
09/04/133 VIT - SCSE

4. Functions
A function groups a number of program statements into a
unit and gives it a name.
This unit can then be invoked from other parts of the
program.
It is used to reduce program size.
The main advantages of using a function are:
1. Easy to write a correct small function
2. Easy to read, write and debug a function
3. Easier to maintain or modify such a function
4. It can be called any number of times in any place with
different parameters
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5. 09/04/135 VIT - SCSE
The Function Declaration
The Function Definition
Function Calling

6. Return statement
The keyword return is used to terminate function and return
a value to its caller.
The return statement may also be used to exit a function
without returning a value.
The general form of the return statement is.
 return;
 return ( expression);
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7. //using multiple return
statements in a function
# include<iostream.h>
void main()
{
float maximum( float, float, float);
float x,y,z,max;
cout<<"Enter three numbers";
cin>>x>>y>>z;
max = maximum(x,y,z);
cout<<"maximum"<<max;
}
float maximum(float a,float b,float c)
{
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if(a>b)
{
if(a>c)
return (a);
else
return (c);
}
else
{
if(b>c)
return (b);
else
return (c);
}
}

8. Types of functions
A function is invoked without passing any formal
argument does not return any value to the calling
portion.
A function is invoked with formal argument and
does not return any value to the calling portion.
A function is invoked with formal argument and
returns back a value to the calling environment.
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9. Function Arguments
The arguments can be classified into two groups:
1. Actual argument
2. Formal argument
Local and Global variable
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10. A function which calls itself directly or indirectly again and again is
known as the recursive function.
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Recursive function
int sum(int n)
{
int value=0;
if(n= = 0)
return(value);
else
value = n+sum(n-1);
return(value);
}
# include<iostream.h>
void main()
{
int sum(int);
int n,temp;
cout<<"Enter any integer
number"<<endl;
cin>>n;
temp = sum(n);
cout<<"value = "<<n<<"and its
sum ="<< temp;
}

11. E.x: void sum(int a,int b,int c=6,int d=10);
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Default arguments
void sum(int a1,int
a2,int a3,int a4)
{
int temp;
temp = a1+a2+a3+a4;
cout<<"sum="<<temp;
}
// default argument declaration
# include<iostream.h>
void sum(int a,int b,int c=6,int d=10);
//default argument
initialization
void main()
{
int a,b,c,d;
cout<<"enter any two
numbers"<<endl;
cin>>a>>b;
sum(a,b); //sum of default values
}

12. 09/04/1312 VIT - SCSE
Function Overloading
cout<<add(5,10);
cout<<add(15,10.0);
cout<<add(12.5,7.5);
cout<<add(5.10,15);
cout<<add(0.75,5);
int add(int a,int b);
int add(int a,int b,int c);
double add(double x,double y);
double add(int p,double q);
double add(double p,int q);

13. 09/04/1313 VIT - SCSE
Function Overloading
double volume(double r,int h)
{
return(3.14519*r*r*h);
}
long volume(long l,int b,int h)
{
return (1*b*h);
}
#include<iostream.h>
int volume(int);
double volume(double,int);
long volume(long,int,int);
main()
{
cout<<volume(10)<< endl;
cout<<volume(2.5,8)<<endl;
cout<<volume(100L,75,15);
getch();
return 0;
}
int volume(int s)
{
return (s*s*s);
}