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Convert.ToInt64 Method (String)

Converts the specified string representation of a number to an equivalent 64-bit signed integer.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

public static long ToInt64(
	string value
)

Parameters

value
Type: System.String
A string that contains a number to convert.

Return Value

Type: System.Int64
A 64-bit signed integer that is equivalent to the number in value, or 0 (zero) if value is null.

ExceptionCondition
FormatException

value does not consist of an optional sign followed by a sequence of digits (0 through 9).

OverflowException

value represents a number that is less than Int64.MinValue or greater than Int64.MaxValue.

Using the ToInt64 method is equivalent to passing value to the Int64.Parse(String) method. value is interpreted by using the formatting conventions of the current thread culture.

If you prefer not to handle an exception if the conversion fails, you can call the Int64.TryParse method instead. It returns a Boolean value that indicates whether the conversion succeeded or failed.

The following example attempts to convert each element in an array of numeric strings to a long integer.


string[] values = { "One", "1.34e28", "-26.87", "-18", "-6.00",
                    " 0", "137", "1601.9", Int32.MaxValue.ToString() };
long result;

foreach (string value in values)
{
   try {
      result = Convert.ToInt64(value);
      Console.WriteLine("Converted the {0} value '{1}' to the {2} value {3}.",
                        value.GetType().Name, value, result.GetType().Name, result);
   }
   catch (OverflowException) {
      Console.WriteLine("{0} is outside the range of the Int64 type.", value);
   }   
   catch (FormatException) {
      Console.WriteLine("The {0} value '{1}' is not in a recognizable format.",
                        value.GetType().Name, value);
   }   
}                                 
// The example displays the following output:
//    The String value 'One' is not in a recognizable format.
//    The String value '1.34e28' is not in a recognizable format.
//    The String value '-26.87' is not in a recognizable format.
//    Converted the String value '-18' to the Int64 value -18.
//    The String value '-6.00' is not in a recognizable format.
//    Converted the String value ' 0' to the Int64 value 0.
//    Converted the String value '137' to the Int64 value 137.
//    The String value '1601.9' is not in a recognizable format.
//    Converted the String value '2147483647' to the Int64 value 2147483647.


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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