Returning from the function is done by using the return statement. The return statement stops execution and returns to the calling function. When a return statement is executed, the function is terminated immediately at that point.

Inline functions can be used to reduce the overheads likes STACKS for small function definition.

The predefined function getchar() is used to get a single character from keyboard and putchar() functions is used to display it.

getchar(), putchar(), gets(), puts()

1. The scope operator reveals the hidden scope of a variable. The scope resolution operator (::) is used for the following purposes.
2. To access a Global variable when there is a Local variable with same name. An example using Scope Resolution Operator.

The pow() function returns base raised to the power of exponent. The sint) function takes a single argument in radians.
#include < iostream >
#include < math.h >
using namespace std;
int main ( )
{
double base, exponent, result;
base = 5;
exponent = 4;
result = pow(base, exponent);
cout < < "pow("< < base < <"˄" < < exponent < <") =" < < result;
double x = 25;
result = sin(x);
cout < < "\nsin("< < x < <")=" < < result;
return 0;
}
Output:
pow(5^4) = 625
sin(25)= -0.132352

C++ provides rich collection of functions ready to be used for various tasks. The tasks to be performed by each of these are already written, debugged and compiled, their definitions alone are grouped and tored in files called header files. Such ready-to-use sub programs are called pre-defined functions Of built-in functions or Library Functions.

toupper(): This function is used to convert the given character into its uppercase. This function will return the uppercase equivalent of the given character. If the given character itself is in upper case, the output will be the same
Syntax:
char toupper( char c);
The following statement will assign the character constant 'K' to the variable c.
char c = toupper('k');

#include < iostream >
using namespace std;
double area(const double r,const double pi=3.14)
{
return(pi*r*r);
}
int main 0
{
double rad,res;
cout << "\nEnter Radius :";
cin >> rad; .
res=area(rad);
cout << "\nThe Area of Circle =" << res;
return 0;
}
Output:
Enter Radius :5
The Area of Circle =78.5

This method copies the address of the actual argument into the formal parameter. Since the address of the argument is passed, any change made in the formal parameter will be reflected back in the actual paratneter.
#include< iostream >
using namespace std;
void display(int & x) //passing address of a//
{
x=x*x;
cout< < "\n\n The Value inside display function (n1 x n1) :"< < x;
}
intmain ( )
{
int n1;
cout< < "\n Enter the Value for N1 :";
cin > > n1;
cout< < "\n The Value of N1 is inside main function Before passing:"< < n1;
display( n1);
cout< < "\n The Value of N1 is inside main function After passing (n1 x n1):"< < n1; return(0);
}
Output:
Enter the Value for N1 :45
The Value of N1 is inside main function Before passing: 45
The Value inside display function (n1 x n1) : 2025
The Value of N1 is inside main function After passing (n1 xn1) : 2025

An inline function looks like normal function in the source file but inserts the function's code directly into the calling program. To make a function inline, one has to insert the keyword inline in the function header.
#include < iostteam >
using name space std;
inline float simple interest(float p1, float n1, float r1)
{
float si1=(p1*n1*r1)/100;
return( si 1);
}
int main ( )
{
float si.p.n,r;
cout < < "\0 Enter the Principle Amount Rs. :";
cin > >p;
cout < < "\0 Enter the Number of Years :";
cin > > n;
cout < < "\0 Enter the Rate ofInterest :";
cin > > r;
si=simple interest(p,n,r);
cout < < "\n The Simple Interest = Rs."< < si;
return 0;
}
Output:
Enter the Principle Amount Rs. :60000
Enter the Number of Years :10
Enter the Rate of Interest :5
The Simple Interest = Rs. 30000

The scope operator reveals the hidden scope of a variable. The scope resolution operator (::) is used for the following purposes. To access a Global variable when there is a Local variable with same name. An example using Scope Resolution Operator.
// Program to show that we can access a global variable
// using scope resolution operator :: when there is a local
// variable with same name //
#include< iostream >
using namespace std;
int x=45; // Global Variable x
int main()
{
int x = 10; // Local Variable x
cout << "\nValue of global x is " << ::x;
cout << "\nValue oflocal x is" << x;
return 0;
}
Output:
Value of global x is 45 .
Value of local x is 10

Inline functions can be used to reduce the overheads like STACKS for small function definition.
An inline function looks like normal function in the source file but inserts the function's code directly into the calling program. To make a function inline, one has to insert the keyword inline in the function header.
Syntax:
inline retuntype functionname( datatype parametemame1, ... datatype parametemameN)
Advantages of inline functions: Inline functions execute faster but requires more memory space. Reduce the complexity of using STACKS.
Example:
#include< iostream >
using namespace std;
inline float simpleinterest(float.pl, float nl, float rl)
{
float si 1=(p1*n1*r1)/100;
retumf si 1);
}
intmain0
{
float si.p,n,r;
cout<< "\nEnter the Principal Amount Rs.:";
cin> p;
cout<< "\nEnter the Number of Years :";
cin<< n;
cout << "\nEnter the Rate ofInterest :";
cin>> r:
si=simpleinterest(p,n,r) ;
cout<< "\nThe Simple Interest = Rs."<< si;
return 0;
}