Integer literals vs Floating point literals in C#

In C#, literals are fixed values written directly in the source code. There are two main categories of numeric literals: integer literals for whole numbers and floating-point literals for decimal numbers. Understanding the difference between these literals is essential for proper variable declaration and avoiding compilation errors.

Integer Literals

An integer literal represents a whole number without a decimal point. Integer literals can be decimal (base 10) or hexadecimal (base 16). A prefix specifies the base: 0x or 0X for hexadecimal, with no prefix for decimal.

Syntax

decimal_literal     // 10, 100, 200
hexadecimal_literal // 0x1A, 0xFF
suffixed_literal    // 10u, 100L, 200UL

Integer Literal Types and Suffixes

Example

using System;

class Program {
   static void Main(string[] args) {
      // Decimal integer literals
      int decimal_val = 200;
      uint unsigned_val = 18u;
      long long_val = 1000L;
      
      // Hexadecimal integer literals
      int hex_val = 0xFF;
      int hex_val2 = 0x1A;
      
      Console.WriteLine("Decimal: " + decimal_val);
      Console.WriteLine("Unsigned: " + unsigned_val);
      Console.WriteLine("Long: " + long_val);
      Console.WriteLine("Hex FF: " + hex_val);
      Console.WriteLine("Hex 1A: " + hex_val2);
   }
}

The output of the above code is −

Decimal: 200
Unsigned: 18
Long: 1000
Hex FF: 255
Hex 1A: 26

Floating-Point Literals

A floating-point literal represents a decimal number with fractional parts. It consists of an integer part, a decimal point, a fractional part, and optionally an exponent part. Floating-point literals can be represented in decimal form or exponential form using e or E.

Syntax

decimal_form     // 3.14, 0.5, 10.0
exponential_form // 1.5e2, 314159E-5F
suffixed_form    // 4.89f, 2.5d, 1.0m

Floating-Point Literal Types and Suffixes

Example

using System;

class Program {
   static void Main(string[] args) {
      // Decimal form
      float float_val = 4.89f;
      double double_val = 3.14159;
      decimal decimal_val = 2.5m;
      
      // Exponential form
      float exp_val1 = 1.5e2f;      // 1.5 * 10^2 = 150
      double exp_val2 = 314159E-5;  // 314159 * 10^-5 = 3.14159
      
      Console.WriteLine("Float: " + float_val);
      Console.WriteLine("Double: " + double_val);
      Console.WriteLine("Decimal: " + decimal_val);
      Console.WriteLine("Exponential 1: " + exp_val1);
      Console.WriteLine("Exponential 2: " + exp_val2);
   }
}

The output of the above code is −

Float: 4.89
Double: 3.14159
Decimal: 2.5
Exponential 1: 150
Exponential 2: 3.14159

Key Differences

Conclusion

Integer literals represent whole numbers and use suffixes like u, L to specify types, while floating-point literals represent decimal numbers and use suffixes like f, d, m. Understanding these literals ensures proper variable declaration and prevents type conversion errors in C# programs.