for variations

Each of the three for sections can be missing, with the consequence that it simply won’t be executed. In a loop like the following, for example:

char c;
int b, m;
for(b = 0, m = 0; m + b <= 4;)
{
     cout << "Is the new student bachelor or master\'s? (b/m) ";
     cin >> c;
     if(c == 'b')
           b++;
     else if(c == 'm')
           m++;
}

the increment part is missing, so it is substituted by the increment statements increasing b and m in the body when appropriate. Notice how such variables both contribute to control the iteration. They are both checked in a sum in the condition section, and both are initialized in comma separated statements in the initialization section.

Example


#include <iostream>
using namespace std;

int main()
{   
     char c;
     int b, m;
     for(b = 0, m = 0; m + b <= 4;)
     {
           cout << "Is the new student bachelor or master\'s? (b/m) ";
           cin >> c;
           if(c == 'b')
                b++;
           else if(c == 'm')
                m++;
     }
     cout << "The number of bachelor students is " << b << " the one of master\'s is " << m;
}

Output

Is new student bachelor or master's? (b/m) b
Is new student bachelor or master's? (b/m) b
Is new student bachelor or master's? (b/m) m
Is new student bachelor or master's? (b/m) b
Is new student bachelor or master's? (b/m) m
The number of bachelor students is 3 the one of master's is 2

C++

for variations

Example

Output