Decimal.Negate() Method in C#

The Decimal.Negate() method in C# is used to return the result of multiplying the specified decimal value by negative one. This method effectively changes the sign of a decimal number − positive numbers become negative and negative numbers become positive.

Syntax

Following is the syntax −

public static decimal Negate(decimal val);

Parameters

• val − The decimal value to negate.

Return Value

Returns a decimal number that is equal to val multiplied by negative one (-1). If val is positive, the result is negative. If val is negative, the result is positive.

Using Decimal.Negate() with Positive Values

The following example demonstrates how Decimal.Negate() converts a positive decimal value to its negative equivalent −

using System;

public class Demo {
   public static void Main() {
      decimal val = 3972.491M;
      Console.WriteLine("Decimal Value = {0}", val);
      Console.WriteLine("HashCode = {0}", (val.GetHashCode()));
      TypeCode type = val.GetTypeCode();
      Console.WriteLine("TypeCode = " + type);
      decimal res = Decimal.Negate(val);
      Console.WriteLine("Negative (Decimal) = " + res);
   }
}

The output of the above code is −

Decimal Value = 3972.491
HashCode = 620041307
TypeCode = Decimal
Negative (Decimal) = -3972.491

Using Decimal.Negate() with Negative Values

When applied to a negative decimal value, Decimal.Negate() returns the positive equivalent −

using System;

public class Demo {
   public static void Main() {
      decimal val = -29.35m;
      Console.WriteLine("Decimal Value = {0}", val);
      Console.WriteLine("HashCode = {0}", (val.GetHashCode()));
      TypeCode type = val.GetTypeCode();
      Console.WriteLine("TypeCode = " + type);
      decimal res = Decimal.Negate(val);
      Console.WriteLine("Negative (Decimal) = " + res);
   }
}

The output of the above code is −

Decimal Value = -29.35
HashCode = 1503969289
TypeCode = Decimal
Negative (Decimal) = 29.35

Practical Example with Zero and Multiple Values

Here's an example showing the behavior of Decimal.Negate() with different types of decimal values including zero −

using System;

public class Demo {
   public static void Main() {
      decimal[] values = { 125.75m, -89.50m, 0.0m, 1000000.99m };
      
      Console.WriteLine("Original\tNegated");
      Console.WriteLine("--------\t-------");
      
      foreach (decimal value in values) {
         decimal negated = Decimal.Negate(value);
         Console.WriteLine("{0}\t\t{1}", value, negated);
      }
   }
}

The output of the above code is −

Original	Negated
--------	-------
125.75		-125.75
-89.50		89.50
0.0		0.0
1000000.99		-1000000.99

Conclusion

The Decimal.Negate() method provides a clean way to change the sign of decimal values in C#. It's equivalent to multiplying by -1 but offers better readability and is specifically designed for decimal operations, making it useful in financial calculations and other precision-critical applications.