Character String

[keithh]

Is this the proper way to put a floating number in an array?

char s[25];
sprintf(s,"%4.1f",winpercent*100.0);

[Athar]

Not really, that would be the C way.

The C++ way looks like this:

stringstream ss;
ss << fixed << setprecision(1) << winpercent*100.0;
string s=ss.str();

[keithh]

does the way i did it work properly tho?

thanks.

[Athar]

Only if winpercent is below a certain size, otherwise you'll have a buffer overflow.

[keithh]

winpercent is always between 0 and 1, so by size do u mean if it has more than 25 digits beyond the decimal point (since s is of size 25)?

and if so, your way resolves that issue?

[Zhuge]

Yes and yes.

[keithh]

i added

#include <sstream>
#include <iostream>

to my visual c++ file, yet i get the error

'stringstream' : undeclared identifier

what am i missing?

[filipe]

You need to fully qualify the name: std::stringstream

Or insert an using declaration before using the name: using std::stringstream;

[keithh]

i'm getting the following error:

'setprecision' : is not a member of 'std'

on this line:

ss << std::fixed << std::setprecision(1) << tempy;

setprecision is a member, so what did i do wrong?

[Null]

#include <iomanip>

[keithh]

still not there yet. i get an error that "s" is now of wrong type when i try to use TextOut.

std::stringstream ss;
ss << std::fixed << std::setprecision(1) << tempy;
std::string s;
s=ss.str();
dc.TextOut(x,y,s,4);

originally, i had s as

char s[25].

[Null]

Try dc.TextOut(x,y,s.c_str(),4);

[keithh]

almost there. ;)

i do this operation in a loop:

std::stringstream ss;
std::string s;
for(z=1;z<10;z++){
ss << std::fixed << std::setprecision(1) << winpercent[z]*100.0;
s=ss.str();
dc.TextOut(x,y,s.c_str(),4);
}

s does not change beyond the first loop. do i need to reset it somehow?

[firedraco]

Actually, you just need to reset ss every loop.

[keithh]

does this code require any release of memory in terms of memory leaks?

thanks.

[filipe]

No. Typically you'll only need to release memory manually if you use new or malloc().

[keithh]

i'm getting an error when the number to be texted is below 10, like 9.8. i guess by specifying "4" in the text out it tries to add the hundreth numeral, which on-screen comes out as a square box. how can i make sure it only texts to the tenth of a point?

[Athar]

By passing the real length of the string.
Replace 4 by s.length().

[keithh]

but the real length could vary hugely, as in 1/6. isn't there a comparable method to %4.1f using this method so i know it will only go to tenths?

[firedraco]

This part: ss << std::fixed << std::setprecision(1) << winpercent[z]*100.0;

is like the "4.1" stuff. After you have done that, the string contains only the parts parts you wanted.