Ceil Function in C

The ceil() function is part of the math library (<math.h>) and is used to round a floating-point number up to the nearest integer greater than or equal to that number. It returns a double value.

Here’s the syntax of the ceil() function:

double ceil(double x);

• x: The floating-point number you want to round up to the nearest integer.

The ceil() function returns the smallest integral value (as a double) that is greater than or equal to x. The returned value is of type double, so you may need to cast it to an integer type if you want an integer result.

Here’s an example of how to use the ceil() function:

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

int main() {
    double num = 5.4;
    double result = ceil(num);

    printf("Original number: %.1lf\n", num);
    printf("Ceiled number: %.1lf\n", result);

    return 0;
}

In this example:

• We include the <math.h> header to use the ceil() function.
• We have a floating-point number num with the value 5.4.
• We use the ceil(num) function to round num up to the nearest integer greater than or equal to it.
• The result is printed, showing that 5.4 is rounded up to 6.0.

Remember that the ceil() function always returns a double-precision floating-point number, so if you need an integer result, you can cast it to an integer type, such as int. For example:

int integerResult = (int)ceil(num);

This will give you the ceiled value as an integer.