Ad:

C++ Discussion Thread
Unsolved
Views: 9631

Page 1
2
3
Next

You are currently viewing page 1 of this multi-page discussion thread

Dec 29th, 2004

Floating point numbers

Expand Post »

i got my program to do stuff, but i wondered if i can take it to the next level...

when a user enters a number of 1458.125478 i got it to do abs.... google is soo good!! but now im wondering if you could display just + or - depending on what is entered. I tried creating an int for the sign to go into but it just doesnt want to know!

then i thought about a string so i went down that route not knowing that you cant combine a string and a float together!

so i had another idea

[php]

int main(){
float n; //n is the number entered

cout << " please input your number with the sign";
cin >> n; // prints everything

cout << n<<endl;

return 0;

}

[/php]

is it possible to put the float which is entered into an array? that way i can chose what is printed out on the screen?

... unless anyone else has other ideas which i welcome

Similar Threads

Floating point numbers in Assembly
Assembly floating point in Assembly
Fixed to Floating point conversions in C
Floating point numbers in C
Dynamic Array, Writing to CSV, Floating Point ?'s in C

Acidburn

Reputation Points: 12

Solved Threads: 5

Posting Pro

Offline

510 posts
since Dec 2004

Permalink

Dec 29th, 2004

Re: Floating point numbers

Quote originally posted by Acidburn ...

but now im wondering if you could display just + or - depending on what is entered.

If it's less than zero, print '-'; otherwise, print '+'.

Quote originally posted by Acidburn ...

is it possible to put the float which is entered into an array?

Of course.

C++ Syntax (Toggle Plain Text)
#include <iostream>
 
int main()
{
   float value[3];
   int i;
   for ( i = 0; i < 3; ++i )
   {
      std::cout << "Please input your number with the sign: ";
      std::cin  >> value[i]; // put user-entered value into an array element
      if ( value[i] < 0 )
      {
         std::cout << "-" << '\n';
      }
      else
      {
         std::cout << "+" << '\n';
      }
   }
   return 0;
}
 
/* my input/output
Please input your number with the sign: 1458.125478
+
Please input your number with the sign: -2.3
-
Please input your number with the sign: 0
+
*/
#include <iostream>

int main()
{
   float value[3];
   int i;
   for ( i = 0; i < 3; ++i )
   {
      std::cout << "Please input your number with the sign: ";
      std::cin  >> value[i]; // put user-entered value into an array element
      if ( value[i] < 0 )
      {
         std::cout << "-" << '\n';
      }
      else
      {
         std::cout << "+" << '\n';
      }
   }
   return 0;
}

/* my input/output
Please input your number with the sign: 1458.125478
+
Please input your number with the sign: -2.3
-
Please input your number with the sign: 0
+
*/

Dave Sinkula

Team Colleague

Reputation Points: 2780

Solved Threads: 312

long time no c

Offline

4,790 posts
since Apr 2004

Permalink

Dec 29th, 2004

Re: Floating point numbers

float value[3];
int i;
for ( i = 0; i < 3; ++i )
{
cout << "Please input your number with the sign: ";
cin >> value[i]; // put user-entered value into an array element
if ( value[i] < 0 )

could you explain that bit a little more so i can try and follow whats going on. From my interpration

you got a float thats an array - true?
you print out the array using the loop i

but one thing i dont get is how do you stop it printing the rest out ? just the sign

Acidburn

Reputation Points: 12

Solved Threads: 5

Posting Pro

Offline

510 posts
since Dec 2004

Permalink

Dec 29th, 2004

Re: Floating point numbers

>could you explain that bit a little more so i can try and follow whats going on.

C++ Syntax (Toggle Plain Text)
   float value[3]; // an array of 3 floats
   int i; // a loop counter
   for ( i = 0; i < 3; ++i ) // loop 3 times
   float value[3]; // an array of 3 floats
   int i; // a loop counter
   for ( i = 0; i < 3; ++i ) // loop 3 times

I can't imagine you're having trouble with that.

C++ Syntax (Toggle Plain Text)
cin >> value[i]; // put user-entered value into an array element
cin >> value[i]; // put user-entered value into an array element

Is this comment confusing?

>you print out the array using the loop i

No. I print a plus or minus. I do so depending on whether the value entered is less than zero.

C++ Syntax (Toggle Plain Text)
if ( value[i] < 0 )
if ( value[i] < 0 )

Dave Sinkula

Team Colleague

Reputation Points: 2780

Solved Threads: 312

long time no c

Offline

4,790 posts
since Apr 2004

Permalink

Dec 29th, 2004

Re: Floating point numbers

ok im going back to my book! I should of known how to do that and i cant belive it was that easy...

Acidburn

Reputation Points: 12

Solved Threads: 5

Posting Pro

Offline

510 posts
since Dec 2004

Permalink

Dec 30th, 2004

Re: Floating point numbers

Intresting topic we have here, I'm wondering if theres a away to just print out the values after the decimal point.

This is what I thought -

If you entered it into a string you'd have some for loop that finds the decimal point and then from their print everything out google has been unsucessful at finding any information regarding this matter

happyHour

Reputation Points: 10

Solved Threads: 0

Newbie Poster

Offline

12 posts
since Dec 2004

Permalink

Dec 30th, 2004

Re: Floating point numbers

Quote originally posted by happyHour ...

Intresting topic we have here, I'm wondering if theres a away to just print out the values after the decimal point.

This is what I thought -

If you entered it into a string you'd have some for loop that finds the decimal point and then from their print everything out google has been unsucessful at finding any information regarding this matter

crude but effective idea would be to change the string to an int. Why well with my little depth of c++ itsall i can think of ... But think about it for a moment you convert it to an int ... What can an int hold?? 4 bytes of real numbers... Whole real numbers! so in feect you'd loose your decimal point. All you have to do then is to take away the number left in the string with the one you created - Hence leaving you with the decimal parts.. .Note that you won't get the 0. xxxxxx Not sure how that works ...

Nor could i code this without research , have a go if your still struggling the forum is always here

Acidburn

Reputation Points: 12

Solved Threads: 5

Posting Pro

Offline

510 posts
since Dec 2004

Permalink

Dec 30th, 2004

Re: Floating point numbers

>I'm wondering if theres a away to just print out the values after the decimal point.
There's a library function in <cmath> called modf that breaks up a floating-point value into its constituent pieces. Alternatively, you could copy the value to an int (which truncates the fractional part) and subtract that from the original floating-point value. Either way, the result is the fractional part of the floating-point value, and you still have access to the whole part.

Narue

Administrator

Reputation Points: 6442

Solved Threads: 1393

Bad Cop

Offline

11,807 posts
since Sep 2004

Permalink

Dec 31st, 2004

Re: Floating point numbers

I have a feeling that in the iostream classes there is a formatting option to set the precision and decimal places. I have never used them myself so i couldnt tell you what they were but a google search should reveal it.

I think it was something along the lines of

C++ Syntax (Toggle Plain Text)
cout.flags( options ... )
or
cout << options... << text
cout.flags( options ... )
or
cout << options... << text

If you cant find it try searching for a hexadecimal number tutorial as hex is a formatting flag which tells cout to display numbers in hexadecimal.... as far as i remember...

1o0oBhP

Reputation Points: 16

Solved Threads: 6

Posting Pro in Training

Offline

445 posts
since Dec 2004

Permalink

Jan 1st, 2005

Re: Floating point numbers

Thanks for the replies, just wondering if you can split up a string of numbers? ... say all the numbers before the decimal point...into string1
and all the others after the decimal point into string 2?

happyHour

Reputation Points: 10

Solved Threads: 0

Newbie Poster

Offline

12 posts
since Dec 2004

Page 1
2
3
Next

This thread is more than three months old

No one has posted to this discussion for at least three months. Please let old threads die and do not reply to them unless you feel you have something new and valuable to contribute that absolutely must be added to make the discussion complete. Otherwise, please start a new thread in this forum instead.

Previous Thread in C++ Forum Timeline: memory

Next Thread in C++ Forum Timeline: Borland C++ vr 4.5

DaniWeb Message

Cancel Changes

User Name
Password