What are floating point literals in C#?

A floating-point literal in C# represents a decimal number that can contain a fractional part. It consists of an integer part, a decimal point, a fractional part, and optionally an exponent part. You can represent floating point literals in either decimal form or exponential form.

Syntax

Following are the different forms of floating-point literal syntax −

// Decimal form
123.45
0.5678

// Exponential form
1.23E+2    // 1.23 × 10²
4.56e-3    // 4.56 × 10?³

// With type suffixes
3.14f      // float
2.718      // double (default)
1.414m     // decimal

Types of Floating-Point Literals

C# supports three floating-point data types, each with specific suffixes −

Using Decimal Form Literals

Example

using System;

class Program {
   static void Main(string[] args) {
      // float literals with 'f' suffix
      float a = 3.56f;
      float b = 3.14159f;
      
      // double literals (default for decimal numbers)
      double c = 9.23456;
      double d = 0.123456789012345;
      
      // decimal literals with 'm' suffix
      decimal e = 123.456789m;
      
      Console.WriteLine("Float a: " + a);
      Console.WriteLine("Float b: " + b);
      Console.WriteLine("Double c: " + c);
      Console.WriteLine("Double d: " + d);
      Console.WriteLine("Decimal e: " + e);
   }
}

The output of the above code is −

Float a: 3.56
Float b: 3.14159
Double c: 9.23456
Double d: 0.123456789012345
Decimal e: 123.456789

Using Exponential Form Literals

Exponential notation uses 'E' or 'e' followed by an exponent to represent very large or very small numbers −

Example

using System;

class Program {
   static void Main(string[] args) {
      // Exponential form literals
      double large = 1.23E+5;     // 1.23 × 10? = 123000
      double small = 4.56E-3;     // 4.56 × 10?³ = 0.00456
      float scientific = 2.99E8f; // Speed of light approximation
      
      Console.WriteLine("Large number: " + large);
      Console.WriteLine("Small number: " + small);
      Console.WriteLine("Scientific notation: " + scientific);
      
      // Mixed usage
      double mixed1 = 269485E-5;  // 2.69485
      float mixed2 = 6.022E23f;   // Avogadro's number approximation
      
      Console.WriteLine("Mixed 1: " + mixed1);
      Console.WriteLine("Mixed 2: " + mixed2);
   }
}

The output of the above code is −

Large number: 123000
Small number: 0.00456
Scientific notation: 299000000
Mixed 1: 2.69485
Mixed 2: 6.022E+23

Common Use Cases

• float: Used for graphics, gaming, and applications where memory is a concern

• double: Default choice for most mathematical calculations and scientific computing

• decimal: Used for financial calculations where precision is critical

• Exponential form: Used for representing very large or very small numbers efficiently

Conclusion

Floating-point literals in C# provide flexible ways to represent decimal numbers using decimal or exponential notation. Choose the appropriate type (float, double, or decimal) based on your precision requirements and use the correct suffix to ensure proper type assignment.