Thread: code explain..

>++frequency[grades[i]]; //----->What is this doing?
frequency is using the value at index i of grades as its own index, then it increments the value stored there. So if grades[i] were 1 and frequency[1] were 0 then frequency[1] would be incremented to 1.

>and what setw() function do for?
It pads output with fill characters to a certain maximum width. By default, the fill character is whitespace, so if you wanted to print 10 in a fixed width of 5 digits, you would say

Code:

cout<< setw ( 5 ) << 10;

Which would then print:

Code:

   10

Instead of:

Code:

10

It's useful for formatting tasks such as the following:

Code:

#include <iomanip>
#include <iostream>

using namespace std;

int main()
{
  for ( int i = 1; i <= 100; i++ ) {
    cout<< setw ( 4 ) << i;
    if ( i % 10 == 0 )
      cout<<endl;
  }
}