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I have a number for example: 2.4444444. I need to get first digit after the dot -- in my case it's 4. How to implement it?

undur_gongor
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LightNight
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4 Answers4

6

How about 

( (int)(floor( fabs( num ) * 10 ) ) ) % 10
Kiril Kirov
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  • You're welcome :) You can even make a constant, let's say `int nNumberAfterDecimalPoint = 1;` and instead of hard-coding `10` (as in my solution), you can make it `( (int)(floor( fabs( num ) * ( 10 * nNumberAfterDecimalPoint ) ) ) % 10`. This will make it a little more flexible and you'll be able to get not only the first digit after the decimal point, but whichever you like only by changing the constant :) Anyway. – Kiril Kirov Nov 17 '11 at 10:33
4

Chech these out! Tried it for you hope it helps

#include<stdio.h>
int main()
 {
  int b;
  float a;
  a=2.4444; 'load some value
  b=(int)a;  'typecast it into integer you get 2 into b variable
  a=a-b;     ' subtract b from a and you will get decimal point value 0.4444        
  a=a*10;    ' multiplying with 10 gives 4.444
  b=(int)a;  ' now apply the same logic again 
  printf("%d",b); 'outputs 4  
 }

Update written these function using these link

Extract decimal part from a floating point number in C

Community
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niko
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1

it could be as simple as

num*10%10
bigOmega ツ
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0
(int)(num * 10) - ((int)num) * 10
Luke
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zmbq
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  • @Wevah is right, you need both - `floor` and `(f)abs`. `(int)` will round the number (for example - 5.6 would become 6 ) – Kiril Kirov Nov 17 '11 at 10:34
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    Typecasting to int doesn't round numbers, it truncates them. At least that's how it's done in almost any computer language I'm aware of. I doubt Object-C is an exception. – zmbq Nov 17 '11 at 10:46