C Program to Check Whether a Number is Negative or Positive

1. Introduction

In various applications, especially when handling data, it's often necessary to determine if a number is positive, negative, or zero. This post will guide you on writing a simple C program to check whether a given number is negative, positive, or zero.

2. Program Overview

1. Take input from the user.

2. Check if the number is greater than, less than, or equal to zero.

3. Display the result.

3. Code Program

#include <stdio.h>

int main() {
    double number;

    // Request user for input
    printf("Enter a number: ");
    scanf("%lf", &number);

    // Check if number is greater than, less than, or equal to zero
    if (number > 0)
        printf("You entered a positive number.");
    else if (number < 0)
        printf("You entered a negative number.");
    else
        printf("You entered zero.");

    return 0;
}

Output:

Enter a number: -5.6
You entered a negative number.

4. Step By Step Explanation

1. We first prompt the user to enter a number. We use a double variable type so that both integer and floating-point numbers can be evaluated.

2. After reading the user's input into the variable number, we perform a series of checks.

3. If the number is greater than zero, it's positive. If it's less than zero, it's negative. If neither of these conditions is met, then the number must be zero.

4. We then display the result based on our evaluation.