Thread: Float to Int

I imagine this is quite simple, probably no more complicated than a cast. Anyway how do you convert a float to int and have it round up or down.

Code:

int num1;
float num2 = 2.6;

num1 = num2 + 0.5;

when you convert from float to int only the integer part of the float is put in the int, to round up add 0.5 which if the float is 2.5 or more will result in the float being 3.1, thus storing 3 in the int.
or if you just want to print a float to a specific precision you can use

Code:

printf(" %.0f ", num2);

Where the .0 is how many decimal places you want, the rounding up is done for you.

The reason I wanted to know is because i'm converting jiffies into hours,minutes and seconds. A jiffy is 1/100th of a second or 0.01 seconds. I've written some code below which should hopefully format it correctly. There is a problem with this code, see the comments for details. The test integer can be changed for test purposes.

Code:

#include <stdio.h>

/*prototypes*/
char* getTime(int clockticks);

int main(){
  char* result;
  int test = 256000;

  result = getTime(test);
  printf("%s\n",result);
  return 0;
}

char* getTime(int clockticks){
  float jiffies,sec,result;
  char* time;
  int min,hr,seconds;

  jiffies = 0.01f;

  result = jiffies * clockticks;
  seconds = result;
  min = seconds/60;
  hr = min/60;

/*This section of code causes some
   problems, I don't want it to display 
   more than 60 in the seconds and minutes
   category, but I do want it to be able
   display for example, 00:04:23 but
   since this is greater than 60 seconds
   it will display 00:04:00 instead.*/
  if(seconds >= 60)
    seconds = 0;
  if(min >= 60)
    min = 0;
  
  if(hr < 10  && min < 10 && seconds < 10)
    sprintf(time,"0%d:0%d:0%d",hr,min,seconds);
  else if(hr < 10 && min < 10)
    sprintf(time,"0%d:0%d:%d",hr,min,seconds);
  else if(hr < 10 && seconds < 10)
    sprintf(time,"0%d:%d:0%d",hr,min,seconds);
  else if(min < 10 && seconds < 10)
    sprintf(time,"%d:0%d:0%d",hr,min,seconds);
  else
    sprintf(time,"%d:%d:%d",hr,min,seconds);
  return time;
}

double floor(double var); Rounds down
double ceil(double var); Rounds up

These can be found in math.h