Check if a Number is Positive or Negative in C Program

Check if a number is positive or negative in c program.

In this article, you will learn how to check whether the input number is a positive or negative number by using the if-else-statement, nested if-else statement, and ternary operator.

Example-1

Example-2

You should know about the following topics in C programming to understand this program:

• C If-else statement
• C Nested if..if-else statement
• C Ternary operator
• C Bitwise operators

1 - Number is Positive or Negative in C

// Check if a Number is Positive or Negative in C
#include <stdio.h>

// It's the main function of the program
int main()
{
    double number;

    // Step-1 Take input from user
    printf("Enter a Number: ");
    scanf("%lf", &number);
    printf("Output :: ");

    // Step-2 Check if the number is negative
    if (number < 0.0)
    {
        printf("NEGATIVE NUMBER\n");
    }

    // Step-3 Check if the number is positive
    else if (number > 0.0)
    {
        printf("POSITIVE NUMBER\n");
    }

    // Step-4 If the previous didn't match then
    else
    {
        printf("You enetered 0\n");
    }
    return 0;
}

Run

Output

2 - Number is Positive or Negative in C using Nested if-else

// Check if a Number is Positive or Negative in C Nested if-else
#include <stdio.h>

// It's the main function of the program
int main()
{
    double number;

    // Step-1 Take input from user
    printf("Enter a Number: ");
    scanf("%lf", &number);
    printf("Output :: ");

    // Step-2 Check if the number is negative
    if (number < 0.0)
    {
        printf("NEGATIVE NUMBER\n");
    }
    else
    {
        // Step-3 Check if the number is positive
        if (number > 0.0)
        {
            printf("POSITIVE NUMBER\n");
        }
        // Step-4 If the previous didn't match then
        else
        {
            printf("You enetered 0\n");
        }
    }
    return 0;
}

Run

Output

3 - Number is Positive or Negative in C using Ternary Operator

// Check if a Number is Positive or Negative in C using Ternary Operator
#include <stdio.h>

// It's the main function of the program
int main()
{
    double number;

    // Step-1 Take input from user
    printf("Enter a Number: ");
    scanf("%lf", &number);
    printf("Output :: ");

    // Step-2 Use the ternary operator to match the value
    number < 0.0
    ?
    printf("NEGATIVE NUMBER\n")
    :
    (
        number > 0.0
        ?
        printf("POSITIVE NUMBER\n")
        :
        printf("You enetered 0\n")
    );
    
    return 0;
}

Run

Output

4 - Number is Positive or Negative in C using Bitwise Operators

// Check if a Number is Positive or Negative in C using Bitwise Operators
#include <stdio.h>

// It's the main function of the program
int main()
{
    int number;

    // Step-1 Take input from user
    printf("Enter a Number: ");
    scanf("%d", &number);
    printf("Output :: ");

    // Step-2 Check if the number is equal to Zero
    if (number == 0)
    {
        printf("You enetered 0\n");
    }
    else
    {
        // Step-3 Extracting the MSB (most significant bit) of the input number
        int msb_num = number & (1 << (sizeof(int) * 8 - 1));

        if (msb_num)
            printf("NEGATIVE NUMBER\n");
        else
            printf("POSITIVE NUMBER\n");
    }

    return 0;
}

Run

Output