Int64.ToString() Method in C#

The Int64.ToString() method in C# is used to convert a 64-bit integer (long) value to its equivalent string representation. This method provides multiple overloads for different formatting options, allowing you to control how the numeric value appears as text.

Syntax

Following are the primary syntax overloads for the Int64.ToString() method −

public override string ToString();
public string ToString(string format);
public string ToString(IFormatProvider provider);
public string ToString(string format, IFormatProvider provider);

Parameters

• format − A numeric format string that specifies how the value should be formatted (optional).

• provider − An object that supplies culture-specific formatting information (optional).

Return Value

Returns a string representation of the Int64 value based on the specified format and culture settings.

Using Basic ToString() Method

The parameterless ToString() method converts the integer to its standard string representation −

using System;

public class Demo {
   public static void Main(){
      long val1 = 0;
      long val2 = Int64.MaxValue;
      long val3 = -123456789;
      
      Console.WriteLine("Value1 = " + val1.ToString());
      Console.WriteLine("Value2 = " + val2.ToString());
      Console.WriteLine("Value3 = " + val3.ToString());
   }
}

The output of the above code is −

Value1 = 0
Value2 = 9223372036854775807
Value3 = -123456789

Using ToString() with Format Strings

The ToString(string format) overload allows you to specify how the number should be formatted using standard numeric format strings −

using System;

public class Demo {
   public static void Main(){
      long val1 = 87987687;
      long val2 = 35436367;
      
      Console.WriteLine("Decimal with 8 digits: " + val1.ToString("D8"));
      Console.WriteLine("Hexadecimal: " + val2.ToString("X"));
      Console.WriteLine("Currency format: " + val1.ToString("C"));
      Console.WriteLine("Number with commas: " + val2.ToString("N0"));
   }
}

The output of the above code is −

Decimal with 8 digits: 87987687
Hexadecimal: 21CB74F
Currency format: $87,987,687.00
Number with commas: 35,436,367

Common Format Strings

Using ToString() with Culture-Specific Formatting

You can also specify culture-specific formatting using IFormatProvider −

using System;
using System.Globalization;

public class Demo {
   public static void Main(){
      long value = 1234567890;
      
      Console.WriteLine("US format: " + value.ToString("N", CultureInfo.CreateSpecificCulture("en-US")));
      Console.WriteLine("German format: " + value.ToString("N", CultureInfo.CreateSpecificCulture("de-DE")));
      Console.WriteLine("French format: " + value.ToString("N", CultureInfo.CreateSpecificCulture("fr-FR")));
   }
}

The output of the above code is −

US format: 1,234,567,890.00
German format: 1.234.567.890,00
French format: 1 234 567 890,00

Conclusion

The Int64.ToString() method provides flexible string conversion for 64-bit integers with support for various format strings and culture-specific formatting. Use format strings like "D", "X", "N", and "C" to control the output representation, and specify culture providers for internationalization requirements.