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× C# Examples


A number is said to be positive if it is greater than zero and it is said to be negative if it is less than zero. A number can be checked for zero, positive and negative using if, if-else, nested if-else and short-hand if-else statements.

Method 1: Using If statement

In the below example, if conditional statements are used to check whether a given number is positive or negative.

using System;

class MyProgram {
  static void CheckNumber(double x) {
    String message = "";
    if (x > 0)
      {message = "Positive number";}
    if (x == 0)
      {message = "Zero";}
    if (x < 0)
      {message = "Negative number";}
    Console.WriteLine(message);
  }  

  static void Main(string[] args) {
    CheckNumber(5.5);
    CheckNumber(-10.8);
  }
}

The above code will give the following output:

Positive number
Negative number

Method 2: Using If-else statement

It can also be achieved using If-else conditional statements.

using System;

class MyProgram {
  static void CheckNumber(double x) {
    String message = "";
    if (x > 0)
      {message = "Positive number";}
    else if (x == 0)
      {message = "Zero";}
    else
      {message = "Negative number";}
    Console.WriteLine(message);
  }  

  static void Main(string[] args) {
    CheckNumber(5.5);
    CheckNumber(-10.8);
  }
}

The above code will give the following output:

Positive number
Negative number

Method 3: Using Nested If-else statement

The above problem can also be solved using nested if-else conditional statements.

using System;
 
class MyProgram {
  static void CheckNumber(double x) {
    String message = "";
    if (x >= 0) {
      if (x > 0)
        message = "Positive number";
      else
        message = "Zero";
    }
    else
      message = "Negative number";
    
    Console.WriteLine(message);
  }  

  static void Main(string[] args) {
    CheckNumber(5.5);
    CheckNumber(-10.8);
  }
}

The above code will give the following output:

Positive number
Negative number

Method 4: Using Ternary Operator

Ternary operator can also be used here.

using System;

class MyProgram {
  static void CheckNumber(double x) {
    String message = "";
    message = (x > 0)? "Positive number" : 
              (x == 0)? "Zero" : "Negative number";
              
    Console.WriteLine(message);
  }  

  static void Main(string[] args) {
    CheckNumber(5.5);
    CheckNumber(-10.8);
  }
}

The above code will give the following output:

Positive number
Negative number




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