[c++] setw probs

b3t4

Hey gain,

anyone know why this is happening....

i read a object name from a class using
classname.getName();

I try to format the ouput, as follows
cout << setw(10) << classname.getName();

BUT
it treats the classname.getName()
as though it is one character rather than,
lets say 5chars long.
Therefore i get
name(followed by 9 spaces)

When what i want is the name followed by
4spaces.

Is this normal???
Any ideas???

Cheers,
A.

davej

I'm a bit rusty with c++ but my immediate solution would be to use printf instead. This will give you complete control over how your output is formatted.

davej

Talliesin

1. printf is evil. Evil I tell you.
   Unless you regularly have to maintain old code you should mentally stick a big Of Historical and C-Compatibility Interest Only warning over everything you know about printf.
2. Normally setw(10) followed by a five-character string should result in 5 spaces, and then the string, rather than the other way around.
   If you neglected to set the alignment to left from the default right then this would result in your formatting being wrong, and you may be misinterpreting which object's spacing is which, leading you to misdiagnose the problem as being with setw.
   Try:
   
   cout << setiosflags(ios::left) << setw(10) << classname.getName();
   

davej

printf is evil. Evil I tell you

Ok I guess this is because it isn't typesafe..
Just out of interest then, what would you use in C++ when you want to do complex String formatting ?

I'm more used to Java (and Perl scripting)

davej

b3t4

sorry ppl,
didnt explain my prob all that well

thing was that when i outputted the name
it was then followed by another name.
i was getting something like:

name somethingElse
longerName somethingNew

When what i wanted was to get something like:

name somethingElse
longerName somethingNew

(above should read somethingNew directly under somethingElse)

in case anyones interested.....
1. set width = 10
2. get the string length
3. width -= length
4. use setw(width) on somethingElse and somethingNew

this will output it in the format i wanted.

using "\t" will work, although it doesnt format the data exactly as may be wanted when there is more than one string after the name. (afaik)

Thanks all,
A.

Talliesin

Ok I guess this is because it isn't typesafe

Not typesafe, low-level, unintuitive, not a natural fit with the rest of the language, hard for the optomiser to get it's teeth into.

I would use stream manipulators as above. There is nothing printf can do that stream manipulators can't do in a clearer fashion.

And unlike the many cases where a C convention is replaced by a higher-level C++ convention efficiency isn't a valid counter argument as stream manipulators tend to be very easily optomised.

I'm more used to Java (and Perl scripting)

Strange that a Java coder would take the non-OO approach