Trusted answers to developer questions
Trusted Answers to Developer Questions

Related Tags

c

What is isfinite() in C?

Kainat Asif

Grokking Modern System Design Interview for Engineers & Managers

Ace your System Design Interview and take your career to the next level. Learn to handle the design of applications like Netflix, Quora, Facebook, Uber, and many more in a 45-min interview. Learn the RESHADED framework for architecting web-scale applications by determining requirements, constraints, and assumptions before diving into a step-by-step design process.

The isfinite() function in C identifies if a number is finite. The declaration of isfinite() is shown below:

int isfinite(float num);

OR:

int isfinite(double num);

OR:

int isfinite(long double num);

Parameter

  • num: the number checked to see if it is finite

Return value

The isfinite() function returns 1 if the number passed as a parameter is finite, and returns 0 otherwise.

Library

To use the isfinite() function, include the following library:

#include <math.h>

Example

Consider the code snippet below, which demonstrates the use of the isfinite() function:

#include<stdio.h>
#include<math.h>
int main() {
float num1 = 1.0;
float num2 = 0.0;
int num3 = isfinite(num1/num2);
if(num3==1){
printf("%f / %f is finite \n", num1, num2);
}else if(num3==0){
printf("%f / %f is infinite \n", num1, num2);
}
int num4 = isfinite(num2/num1);
if(num4==1){
printf("%f / %f is finite \n", num2, num1);
}else if(num4==0){
printf("%f / %f is infinite \n", num2, num1);
}
int num5 = isfinite(INFINITY);
if(num5==1){
printf("INFINITY is finite \n");
}else if(num5==0){
printf("INFINITY is infinite \n");
}
return 0;
}

Explanation

  • The isfinite() function is used in line 8 to show that a division by zero is not finite.
  • The isfinite() function is used in line 15 and a simple finite division is performed. The isfinite() function returns 0, as the division is finite.
  • The isfinite() function is used in line 22 to show that infinity is not finite.

RELATED TAGS

c

CONTRIBUTOR

Kainat Asif
Copyright ©2022 Educative, Inc. All rights reserved

Grokking Modern System Design Interview for Engineers & Managers

Ace your System Design Interview and take your career to the next level. Learn to handle the design of applications like Netflix, Quora, Facebook, Uber, and many more in a 45-min interview. Learn the RESHADED framework for architecting web-scale applications by determining requirements, constraints, and assumptions before diving into a step-by-step design process.

Keep Exploring