C Program to Check Whether a Number is Positive or Negative
This program takes a number from the user and checks whether that number is either positive or negative or zero.
Example #1: Check if a Number is Positive or Negative Using if…else
You can also solve this problem using nested if else statement.
#include <stdio.h>
int main()
{
double number;
printf("Enter a number: ");
scanf("%lf", &number);
if (number <= 0.0)
{
if (number == 0.0)
printf("You entered 0.");
else
printf("You entered a negative number.");
}
else
printf("You entered a positive number.");
return 0;
}Example #2: Check if a Number is Positive or Negative Using Nested if…else
#include <stdio.h>
int main()
{
double number;
printf("Enter a number: ");
scanf("%lf", &number);
// true if number is less than 0
if (number < 0.0)
printf("You entered a negative number.");
// true if number is greater than 0
else if ( number > 0.0)
printf("You entered a positive number.");
// if both test expression is evaluated to false
else
printf("You entered 0.");
return 0;
}Output 1
Enter a number: 12.3 You entered a positive number.
Output 2
Enter a number: 0 You entered 0.
program in C that checks whether a given number is positive or negative:
#include <stdio.h>
int main() {
float num;
printf("Enter a number: ");
scanf("%f", &num);
if (num > 0) {
printf("%.2f is a positive number.\n", num);
} else if (num < 0) {
printf("%.2f is a negative number.\n", num);
} else {
printf("You entered zero.\n");
}
return 0;
}
In this program, we declare a float variable “num”, which represents the number we want to check for positivity or negativity. We prompt the user to enter this value using the “scanf” function.
We then use an “if-else” statement to determine whether the number is positive or negative. If the number is greater than 0, we print out a message indicating that it is positive. If the number is less than 0, we print out a message indicating that it is negative. Finally, if the number is equal to 0, we print out a message indicating that it is neither positive nor negative.
Finally, we return 0 from the main function to indicate that the program has executed successfully. The output of this program would be:
Enter a number: 7.5
7.50 is a positive number.
If the user had entered a negative number, such as -3.2, the output would be:
Enter a number: -3.2
-3.20 is a negative number.