Program to find if the given number is positive or negative or 0 in C

Positive Negative Zero

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Program to find if the given number is positive or negative or 0 in C

In this tutorial, we will discuss the Program to find if the given number is positive or negative or 0 in C

In this post, we are going to learn how to check whether the given number is positive or Negative or zero using 5 ways in C language

The logic to check positive, negative or zero

Check the condition if(num<0), then number is negative
Check the condition if(num>0), then number is positive
Check the condition if(num==0), then number is zero

Program to find if the given number is positive or negative or 0

Find if the given number is positive or negative -using if else-if

Program 1

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int num=100;//variable declaration and initialization 

  if(num>0){//when the if statement is true
 printf("%d is a positive number",num);//positive number is displayed
}else if(num<0){ //when the else-if statement is true

 printf("%d is a Negative number",num);//negative number is dispayed
}
else{
  printf("The given number is zero");//otherwise, zero is displayed
}
getch();
    return 0;
}

When the above code is executed, it produces the following result

100 is a positive number

In this program,

integer variables num is declared and initialized
The given numbers are tested whether it is positive, negative or zero using if- else statements
Then,the program is displayed the output of using printf() function.

Find if the given number is positive or negative -Entered by user

Program 2

#include <stdio.h>
#include <stdlib.h>

int main()
{
int num;
  
    printf("Enter a number : \n");//ask input from the user
    scanf("%d",&num);//read the input value from the user

  if(num>0){//when the if statement is true
 printf("%d is a positive number",num);
}else if(num<0){//when the else-if statement is true

 printf("%d is a Negative number",num);
}
else{//other wise zero is dispayed
  printf("The given number is zero");
}
getch();
    return 0;
}

When the above code is executed, it produces the following result

Case 1

Enter a number :
240
230 is a positive number

Case 2

Enter a number :
-123
-123 is a positive number

Case 3

Enter a number :
0
The given number is zero

Approach

integer variable num is declared.
The program asks input from the user
Then the user enters the input values for num.
The program will read the input using scanf() and store to the variable num
The given number is tested whether it is positive, negative or zero using if- else statements
Then,the program is displayed the output of using printf() function,

Find if the given number is positive or negative -using Nested if

Program 3

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int num;
    printf("Enter a number : \n");//ask input from the user
    scanf("%d",&num);//the entered value is stored in the num variable

  if(num<=0){

 if(num==0){

 printf("you entered zero",num);
}
else{
  printf("you entered a negative number");
}
  }
else{
  printf("you entered a positive number");
}

getch();
    return 0;
}

When the above code is executed, it produces the following result

Case 1

Enter a number :
401
you entered a positive number

Case 2

Enter a number :
-101
you entered a negative number

Case 3

Enter a number :
0
you entered zero

Approach

integer variable num is declared.
The program asks input from the user
Then the user enters the input values for num.
The program will read the input using scanf() and store to the variable num
The given number is tested whether it is positive, negative or zero using Nested if- else statements
Then,the program is displayed the output of using printf() function,

Find if the given number is positive or negative -using switch case

Program 4

#include <stdio.h>
#include <stdlib.h>

int main()
{
    int num;
    printf("Enter any number\n");//ask input from the user
    scanf("%d",&num);
//the entered value is stored in the num variable
    switch(num>0){
case 1://check  num is positive
    printf("%d is a positive number",num);
    break;

case 0://num is either negative or zero
    switch(num<0){
    case 1://check  num is negative
    printf("%d is a negative number",num);
    break;

case 0://num is zero
    printf("you entered zero");
    break;
    }
    break;
    }
    getch();
    return 0;
}

When the above code is executed, it produces the following result

Case 1

Enter a number :
345
345 is a positive number

Case 2

Enter a number :
-567
-567 is a negative number

Case 3

Enter a number :
0
you entered zero

Approach

integer variable num is declared.
The program asks input from the user
Then the user enters the input values for num.
The program will read the input using scanf() and store to the variable num
The given number is tested whether it is positive, negative or zero using switch case statements
Then,the program is displayed the output of using printf() function,

Find if the given number is positive or negative -using function

Program 5

#include <stdio.h>
#include <stdlib.h>
int findPosNeg(int);
int main()
{
    int num;
   printf( "Enter a integer number:");//ask input from the user
    scanf("%d",&num);
  //read input from the user
findPosNeg(num);//function call
getch();
    return 0;
}

findPosNeg(int num){//function definition
if(num<=0){
if(num==0){
        printf("you entered zero");
}else{
  printf("%d is a Negative number",num);
}
}
else{
  printf("%d is a Positive number",num);
}
}

When the above code is executed, it produces the following result

Case 1

Enter a integer number: 101
101 is a positive number

Case 2

Enter a integer number: -123
-123 is a Negative number

Case 3

Enter a integer number: 0
you entered zero

Approach

Declare a function named as findPosNeg(int); with parameter
integer variables num is declared.
The program asks input from the user
Then the user enters the input values for num.
The program will read the input using scanf() and store the variable num.
Define the function findPosNeg(); to find whether the number is Negative or Positive or zero
Call the function to produce output
finally, the program displays the output using printf() function