C++ cout setw() integer width cout modifiers

#include <iostream>
using namespace std;
#include <iomanip.h>
int main()//from w ww. jav  a2s  .  com
{
   cout << 456 << 456 << 456 << "\n";   
   cout << setw(5) << 456 << setw(5) << 456 << setw(5) << 456 << "\n";          
   cout << setw(7) << 456 << setw(7) << 456 << setw(7) << 456 << " \n";        
   return 0;
}