4 replies to this topic

[kumamako]

what really is the difference between using setw function and width(). Are they the same thing? can someone give me an example of each please.

[ZekeDragon]

Uhh... are you referring to C++ character streams? Or is this some kind of GUI library you're talking about? Info man, info!

Anyway, the differences between using setw and width() in the C++ ostreams are marginal, nothing more than syntax as far as I know. The documentation goes so far to say that setw is nothing more than a call to the width() member.

The only real difference is with width() you don't have to include the iomanip lib, whereas if you use setw you must explicitly #include <iomanip>.

- Zeke

[MathX]

And what about between cout.precision() and setprecision()? Is that all the same too?

[ZekeDragon]

I refer to these guys a lot.

The manipulator setprecision behaves as a call to the member function ios_base::precision(). Again, it seems the only real difference is preference and the need to include <iomanip>. However, a small difference I notice is with the "fixed" manipulator:

float f = 3.14159;

cout << setprecision(9) << f << endl; // prints "3.14159"

cout << fixed << setprecision(9) << f << endl; // prints "3.141590000"

Whereas with cout.precision() this would require two seperate function calls.

float f = 3.14159;

cout.precision(9);

cout << f << endl; // prints "3.14159"

cout.setf(ios::fixed, ios::floatfield); //when a float is provided, the precision is fixed.

cout << f << endl; // prints "3.141590000"

I'd use the manipulators from <iomanip> personally since they're a bit more self documenting and easier, at least for me, to read. The differences are marginal though.

- Zeke

[MathX]

Thanx m8 :)