How to Convert String to Double in C#.Net [Different Methods]

Converting a string to a double in C# is a common task when dealing with numerical data. There are several methods to convert string to double in C#. In this tutorial, we will go through different methods to convert a string to a double in C#.Net.

Table of Contents

How to Convert String to Double in C#.Net

Here are the different methods to convert string to double in C#.Net.

Method 1: Using Double.Parse()

Double.Parse() is a method that converts a string representation of a number to its double-precision floating-point equivalent in C#.Net.

Example:

using System;

class Program
{
    static void Main()
    {
        string strNumber = "123.45";
        double doubleNumber = Double.Parse(strNumber);
        Console.WriteLine(doubleNumber);
    }
}

This program converts the string “123.45” to a double and prints it to the console. You can see the output like below:

Method 2: Using Convert.ToDouble()

You can also use the Convert.ToDouble() method in C#.Net which is a part of the System namespace. This method is similar to Double.Parse() but provides a unified approach for converting different types to double.

Example:

using System;

class Program
{
    static void Main()
    {
        string strNumber = "123.45";
        double doubleNumber = Convert.ToDouble(strNumber);
        Console.WriteLine(doubleNumber);
    }
}

Method 3: Using Double.TryParse()

The Double.TryParse() method is similar to Double.Parse(), but it does not throw an exception if the conversion fails. Instead, it returns a boolean value indicating whether the conversion succeeded or not.

Example:

using System;

class Program
{
    static void Main()
    {
        string strNumber = "123.45";
        double doubleNumber;
        bool isParsed = Double.TryParse(strNumber, out doubleNumber);
        
        if (isParsed)
        {
            Console.WriteLine(doubleNumber);
        }
        else
        {
            Console.WriteLine("Conversion Failed.");
        }
    }
}

Method 4: Using Invariant Culture

Sometimes the string representation of a double might have a different format depending on the culture (e.g. using a comma instead of a period as a decimal separator). You can use the Double.Parse() method with the CultureInfo.InvariantCulture to ensure that the conversion is culture-independent.

Example:

using System;
using System.Globalization;

class Program
{
    static void Main()
    {
        string strNumber = "123,45";
        double doubleNumber = Double.Parse(strNumber, CultureInfo.InvariantCulture);
        Console.WriteLine(doubleNumber);
    }
}

Method 5: Using Custom NumberStyles

If your string representation has custom formats, you can specify custom NumberStyles to handle different number representations.

Example:

using System;
using System.Globalization;

class Program
{
    static void Main()
    {
        string strNumber = "123.45";
        double doubleNumber = Double.Parse(strNumber, NumberStyles.AllowDecimalPoint | NumberStyles.AllowThousands, CultureInfo.InvariantCulture);
        Console.WriteLine(doubleNumber);
    }
}

Conclusion

In this tutorial, we explored different ways to convert a string to a double in C#.Net. The method you choose depends on the specific requirements of your application. In general, Double.Parse() and Convert.ToDouble() are the most straightforward options, while Double.TryParse() is useful for error handling, and custom NumberStyles are useful for parsing strings in specific formats.