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C# double Keyword with Example

In this tutorial, we will learn about the double keyword, its usage, memory size with example in C#. By IncludeHelp Last updated : April 04, 2023

C# double Keyword

The double keyword is used to declare a variable that can store a floating point value between the range of ±1.5 x 10⁻⁴⁵ to ±3.4 x 10³⁸. The double is an alias of System.Single.

It occupies 8 byte (64 bits) space in the memory.

Note: Any floating point value without using any suffix is considered as a double value. We can also specify a suffix d or D to represent a double value.

Syntax

double variable_name = value;

Example of double keyword in C#

Here, we are declaring a double variable num, initializing it with the value 12345.6789 and printing its value, type, and size of a double type variable.

using System;
using System.Text;

namespace Test {
  class Program {
    static void Main(string[] args) {
      //variable declaration
      double num = 12345.6789;

      //printing value
      Console.WriteLine("num: " + num);
      //printing type of variable
      Console.WriteLine("Type of num: " + num.GetType());
      //printing size
      Console.WriteLine("Size of a double variable: " + sizeof(double));
      //printing minimum & maximum value of double
      Console.WriteLine("Min value of double: " + double.MinValue);
      Console.WriteLine("Max value of double: " + double.MaxValue);

      //hit ENTER to exit
      Console.ReadLine();
    }
  }
}

Output

num: 12345.6789
Type of num: System.Double
Size of a double variable: 8
Min value of double: -1.79769313486232E+308
Max value of double: 1.79769313486232E+308

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