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Convert.ToInt32 Method (String)

Converts the specified string representation of a number to an equivalent 32-bit signed integer.

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

public static int ToInt32(
	string value
)

Parameters

value
Type: System.String

A string that contains the number to convert.

Return Value

Type: System.Int32
A 32-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 Int32.MinValue or greater than Int32.MaxValue.

Using the ToInt32(String) method is equivalent to passing value to the Int32.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 Int32.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 a numeric string array to an integer.

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

foreach (string value in values)
{
   try {
      result = Convert.ToInt32(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 Int32 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 Int32 value -18. 
//    The String value '-6.00' is not in a recognizable format. 
//    Converted the String value ' 0' to the Int32 value 0. 
//    Converted the String value '137' to the Int32 value 137. 
//    The String value '1601.9' is not in a recognizable format. 
//    Converted the String value '2147483647' to the Int32 value 2147483647.

.NET Framework

Supported in: 4.6, 4.5, 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

.NET for Windows Store apps

Supported in: Windows 8

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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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