Number entered is positive, negative or zero using nested if-else

C program to check whether a number is positive, negative or zero using nested if-else.

Program

#include<stdio.h>
#include<conio.h>
void main()
{
	int num;

    printf("Enter a number\t: ");
    scanf("%d",&num);

    if(num >= 0)
    {
        if(num == 0)
            printf("Number entered is zero");
        else
            printf("Number entered is positive");
    }
    else
        printf("Number entered is negative");

    getch();
}

Output

********** Run1 **********

Enter a number  : 23
Number entered is positive


********** Run2 **********

Enter a number  : -21
Number entered is negative


********** Run3 **********

Enter a number  : 0
Number entered is zero

Explanation

A number is taken as an input from the user and stored in the variable named say 'num'
First of all, condition (num >= 0) is checked.
If true, then the number is either zero or a positive value. So, checked for both the cases one by one using another if else construct.
If false, then the number is a negative number.