c++ how to call a function code example
Example 1: function call in c++
#include <iostream>
using namespace std;
//REMOVE COMMENTS TO USE VARIOUS FUNCTION CALLING METHODS
// function declaration
void swaper(int &,int&) ;// call by reference
//void swaper(int *,int * );// call by address
//void swaper(int,int );//call by value
int main () {
// local variable declaration:
int a = 100;
int b = 200;
/* calling a function to swap the values using variable reference.*/
swaper(a, b);// call by reference
//swaper(&a, &b); //call by address
//swaper(a, b); // call by value
cout << "After swap, value of a :" << a << endl;
cout << "After swap, value of b :" << b << endl;
return 0;
}
//CALL BY refernce DEFINATION
void swaper(int &x, int &y) // x and y are ref variable..ie they are other name for a and b
{
int temp;
temp = x; //save the value as x which is ref for a
x = y; // put y into x
y = temp; // put x into y
}
//CALL BY ADD DEFINATION
/*void swaper(int *x, int *y) {
int temp;
temp = *x; //save the value at address x
*x = *y; // put y into x
*y = temp; // put x into y
*/
// CALL BY VALUE DEFINATION
/* void swaper(int x, int y) {
int temp;
temp = x; // save the value of local x
x = y; // put local y into local x
y = temp; //put local x into local y
*/
Example 2: how to declare a function in c++
// function example
#include <iostream>
using namespace std;
int addition (int a, int b)
{
int r;
r=a+b;
return r;
}
Example 3: function declerations in C++
#include <iostream>
#include <stdlib.h>
#include <iomanip>
#include <fstream>
using namespace std;
void function_one(double, double, double);
int main() {
double r1 = 1.0;
double r2 = 2.0;
double x = 0.0;
function_one(r1, r2, x);
return 0;
}
void function_one(double rmin, double rmax, double x0) {
cout << "Function got called" << endl;
}