Check whether the given number is positive or negative or 0 in C++

Positive Negative Zero

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Check whether the given number is positive or negative or 0 in C++

In this tutorial, we will discuss the Check whether 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

Check whether the given number is positive or negative or 0

Code to find whether the given number is positive or negative or 0 – using if else

Program 1

#include <iostream>
#include <conio.h>
using namespace std;

int main()
{
    int num=-100;

  if(num>0){
 cout<<num<<" is a positive number";
}else if(num<0){

  cout<<num<<" is a negative number";
}
else{
  cout<<"The given number is zero";
}
getch();
    return 0;
}

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

-100 is a negative 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 cout<<

Code to find whether the given number is positive or negative or 0 -Entered by user

Program 2

#include <iostream>
#include <conio.h>
using namespace std;

int main()
{
    int num;
    cout<<"Enter a number: ";
    cin>>num;

  if(num>0){
 cout<<num<<" is a positive number";
}else if(num<0){

  cout<<num<<" is a negative number";
}
else{
  cout<<"The given number is zero";
}
getch();
    return 0;
}

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

Case 1

Enter a number: 4321
4321 is a positive number

Case 2

Enter a number:-7891
-7891 is a negative number

Case 3

Enter any 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 cin>> 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 cout<< ,

Code to find whether the given number is positive or negative or 0 – using Nested if

Program 3

#include <iostream>
#include <conio.h>
using namespace std;

int main()
{
    int num;
    cout<<"Enter a number : \n";
    cin>>num;

  if(num<=0){

 if(num==0){

 cout<<num<<"you entered zero";
}
else{
  cout<<"you entered a negative number";
}
  }
else{
  cout<<"you entered a positive number";
}

getch();
    return 0;
}

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

Case 1

Enter a number:
5678
You entered a positive number

Case 2

Enter a number:
-765
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 cin>> 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 cout<< ,

Code to find whether the given number is positive or negative or 0 – using switch case

Program 4

#include <iostream>
#include <conio.h>
using namespace std;

int main()
{
    int num;
    cout<<"Enter any number\n";
    cin>>num;

    switch(num>0){
case 1://check  num is positive
    cout<<num<<" is a positive number";
    break;

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

case 0://check  num is negative
    cout<<"you entered zero";
    break;
    }
    break;
    }
    getch();
    return 0;
}

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

Case 1

Enter any number
1000
1000 is a positive number

Case 2

Enter any number
-789
-789 is a negative number

Case 3

Enter any 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 cin>> 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 cout<< ,

Code to find whether the given number is positive or negative or 0 – using function

Program 5

#include <iostream>
#include <conio.h>
using namespace std;

#include <stdlib.h>
int findPosNeg(int);//function prototype
int main()
{
    int num;
   cout<<"Enter a integer number:";
    cin>>num;
  //read input from the user
findPosNeg(num);//function call
getch();
    return 0;
}

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

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

case 1

Enter a integer number:675
675 is a positive number

case 2

Enter a integer number: -786
-786 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 cin>> 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 cout<<.