C floor() Function

Posted in C Tutorial

Updated on Jan 12, 2024

By Mari Selvan

👁️ 159 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In C programming, the floor() function is a part of the <math.h> library, and it is used to round a floating-point number down to the nearest integer less than or equal to it.

This function is particularly useful when precise integer values are required, and rounding towards the lower integer is desired.

In this tutorial, we'll explore the usage and functionality of the floor() function in C.

💡 Syntax

The syntax for the floor() function is as follows:

Syntax

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double floor(double x);

x: The floating-point number to be rounded down.

📄 Example

Let's dive into an example to illustrate how the floor() function works.

floor.c

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#include <stdio.h>
#include <math.h>

int main() {
  double number = 5.78;

  // Round down to the nearest integer
  double result = floor(number);

  printf("Original number: %.2f\n", number);
  printf("Rounded down: %.2f\n", result);

  return 0;
}

💻 Output

Output

Original number: 5.78
Rounded down: 5.00

🧠 How the Program Works

In this example, the floor() function is used to round down the floating-point number 5.78 to the nearest integer, and the result is printed.

↩️ Return Value

The floor() function returns a double value representing the largest integral value less than or equal to the provided argument.

📚 Common Use Cases

The floor() function is commonly used in situations where decimal values need to be truncated towards the lower integer. For example, when dealing with pricing or quantities in certain applications, rounding down ensures a conservative approach.

📝 Notes

The <math.h> header file must be included to use the floor() function.
It's important to note that the floor() function returns a double even though the result is an integer. If an integer result is specifically needed, type casting may be applied.

🎢 Optimization

The floor() function is generally efficient, and optimization is not typically a concern. Ensure that the appropriate header file is included and handle the result data type accordingly.

🎉 Conclusion

The floor() function in C is a valuable tool for rounding down floating-point numbers to the nearest integer. It provides precision when dealing with numerical values that require a conservative approach towards lower integers.

Feel free to experiment with different floating-point numbers and explore how the floor() function behaves in various scenarios. Happy coding!