How to compare two double values in C#

Overview

We use the CompareTo() method to compare two double values or objects in Ruby. Remember that a double value in C# represents a double-precision, floating-point number.

When we compare two double values, say d1 and d2, the CompareTo() method returns an integer that is less than 1 if the latter is lesser than the former. It returns 0 if they are both equal, or just 1 if the latter is greater.

Syntax

public int CompareTo (double d);
Syntax for Comparing Two Double Values

Parameters

d: This is the decimal to compare.

Return value

The value returned is an integer. This method returns a signed number that indicates whether a particular double instance is greater, lesser than, or equal to d. 1 is returned if the instance is greater than d. -1 is returned if the instance is lesser than d, and 0 is returned if the instance and d are equal.

Code example

// use System
using System;
// create class
class DoubleComparer
{
    // main method
    static void Main()
    {
      // create double values
      double doubleNumberOne = 23.454;
      double doubleNumberTwo = doubleNumberOne * 1;
      double doubleNumberThree = 45.34;
      // comparing values and printing results
      Console.WriteLine(doubleNumberOne.CompareTo(doubleNumberTwo));  // 0 : Equal
      Console.WriteLine(doubleNumberOne.CompareTo(doubleNumberThree));  // -1 : lesser than
      Console.WriteLine(doubleNumberThree.CompareTo(doubleNumberOne));  // 1 : greater than
    }
}

Code explanation

  • Lines 10–12: We instantiate the double variables d1, d2, and d3 and initialize them with values.
  • Line 15: We compare d1 to d2, and it returns 0.
  • Line 16: We compare d1 to d3, and it returns -1.
  • Line 17: We compare d3 to d1, and it returns 1.

Free Resources

License: Creative Commons-Attribution-ShareAlike 4.0 (CC-BY-SA 4.0)