C++/Console/cout width

cout: width(), precision(), and fill().

<source lang="cpp">

1. include <iostream>

using namespace std;

int main() {

 cout.setf(ios::showpos); 
 cout.setf(ios::scientific); 
 cout << 123 << " " << 123.23 << endl; 

 cout.precision(2);                 // two digits after decimal point 
 cout.width(10);                    // in a field of 10 characters 
 cout << 123 << " "; 
 cout.width(10);                    // set width to 10 
 cout << 123.23 << endl; 

 cout.fill("#");                    // fill using # 
 cout.width(10);                    // in a field of 10 characters 
 cout << 123 << " "; 
 cout.width(10);                    // set width to 10 
 cout << 123.23; 

 return 0; 

}

 </source>

Create a table of log10 and log from 2 through 100.

<source lang="cpp">

1. include <iostream>
2. include <cmath>

using namespace std; int main() {

 double x;
 cout.precision(5);
 cout << "         x       log x        ln e\n\n";
 for(x = 2.0; x <= 100.0; x++) {
   cout.width(10);
   cout << x << "  ";
   cout.width(10);
   cout << log10(x) << "  ";
   cout.width(10);
   cout << log(x) << "\n";
 }

 return 0;

}

 </source>

Left-justification and right-justification.

<source lang="cpp">

1. include <iostream>
2. include <iomanip>

using std::cout; using std::endl; using std::ios; using std::setw; using std::setiosflags; using std::resetiosflags; int main() {

  int x = 12345;
  cout << "Default is right justified:\n"
       << setw(10) << x << "\n\nUsing Member Functions" 
       << "\nUse setf to set ios::left:\n" << setw(10);
  
  return 0;

}

 </source>

Set cout length

<source lang="cpp">

1. include <iostream>
2. include <cstring>

using namespace std; void center(char *s); int main() {

 center("www.java2s.com!");
 center("www.java2s.com");
 return 0;

} void center(char *s) {

 int len;
 len = 40+(strlen(s)/2);
 cout.width(len);
 cout << s << "\n";

}

 </source>