C++ : Default Arguments

Example:1

#include <iostream>

using namespace std;
void cal(int n1=10,int n2=20,int n3=30,int n4=40)
{
    int s;
    s=n1+n2+n3+n4;
    cout<<"Sum ="<<s<<endl;
}
int main()
{
    cal();//1
    cal(1);//2
    cal(1,2); //3
    cal(1,2,3); //4
    cal(1,2,3,4); //5
    cal(10,2,5,3); //6
    return 0;
}

Output:

Sum =100
Sum =91
Sum =73
Sum =46
Sum =10
Sum =20

Example:2

#include <iostream>

using namespace std;
void line1(char ch='-',int n=10)
{
    int i;
    for(i=1;i<=n;i++)
    {
        cout<<ch;
    }
    cout<<endl;
}
int main()
{
    line1(); //1 - 10 times
    line1('*'); //2 * 10 times
    line1('$',5);//3 $ 5 times
    line1('#',30);//4 # 30 times
    return 0;
}

Output:

———-
**********
$$$$$
##############################

Example:3

#include <iostream>

using namespace std;
void cal(int=5,int=2,int=32,int=20);
int main()
{
    cal();//1
    cal(1);//2
    cal(1,2); //3
    cal(1,2,3); //4
    cal(1,2,3,4); //5
    cal(10,2,5,3); //6
    return 0;
}
void cal(int n1,int n2,int n3,int n4)
{
    int s;
    s=n1+n2+n3+n4;
    cout<<"Sum ="<<s<<endl;
}

Output:

Sum =59
Sum =55
Sum =55
Sum =26
Sum =10
Sum =20