Converts the specified
String representation of a number to an equivalent 32-bit signed integer.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Visual Basic (Declaration)
Public Shared Function ToInt32 ( _
value As String _
) As Integer
Dim value As String
Dim returnValue As Integer
returnValue = Convert.ToInt32(value)
public static int ToInt32 (
string value
)
public:
static int ToInt32 (
String^ value
)
public static int ToInt32 (
String value
)
public static function ToInt32 (
value : String
) : int
Parameters
- value
A String containing a number to convert.
Return Value
A 32-bit signed integer equivalent to the value of value.
-or-
Zero if value is a null reference (Nothing in Visual Basic).
The return value is the result of invoking the Int32.Parse method on value.
The following code example converts String representations of 32-bit integers with the ToInt32 method, using default formatting.
' Example of the Convert.ToInt32( String ) and
' Convert.ToInt32( String, IFormatProvider ) methods.
Imports System
Imports System.Globalization
Imports Microsoft.VisualBasic
Module ToInt32ProviderDemo
Dim format As String = "{0,-20}{1,-20}{2}"
' Get the exception type name; remove the namespace prefix.
Function GetExceptionType( ex As Exception ) As String
Dim exceptionType As String = ex.GetType( ).ToString( )
Return exceptionType.Substring( _
exceptionType.LastIndexOf( "."c ) + 1 )
End Function
Sub ConvertToInt32( numericStr As String, _
provider As IFormatProvider )
Dim defaultValue As Object
Dim providerValue As Object
' Convert numericStr to Int32 without a format provider.
Try
defaultValue = Convert.ToInt32( numericStr )
Catch ex As Exception
defaultValue = GetExceptionType( ex )
End Try
' Convert numericStr to Int32 with a format provider.
Try
providerValue = Convert.ToInt32( numericStr, provider )
Catch ex As Exception
providerValue = GetExceptionType( ex )
End Try
Console.WriteLine( format, numericStr, _
defaultValue, providerValue )
End Sub
Sub Main( )
' Create a NumberFormatInfo object and set several of its
' properties that apply to numbers.
Dim provider As NumberFormatInfo = new NumberFormatInfo( )
' These properties affect the conversion.
provider.NegativeSign = "neg "
provider.PositiveSign = "pos "
' These properties do not affect the conversion.
' The input string cannot have decimal and group separators.
provider.NumberDecimalSeparator = "."
provider.NumberGroupSeparator = ","
provider.NumberGroupSizes = New Integer( ) { 3 }
provider.NumberNegativePattern = 0
Console.WriteLine( "This example of" & vbCrLf & _
" Convert.ToInt32( String ) and " & vbCrLf & _
" Convert.ToInt32( String, IFormatProvider ) " & _
vbCrLf & "generates the following output. It " & _
"converts several strings to " & vbCrLf & "Integer " & _
"values, using default formatting " & _
"or a NumberFormatInfo object." & vbCrLf )
Console.WriteLine( format, "String to convert", _
"Default/exception", "Provider/exception" )
Console.WriteLine( format, "-----------------", _
"-----------------", "------------------" )
' Convert strings, with and without an IFormatProvider.
ConvertToInt32( "123456789", provider )
ConvertToInt32( "+123456789", provider )
ConvertToInt32( "pos 123456789", provider )
ConvertToInt32( "-123456789", provider )
ConvertToInt32( "neg 123456789", provider )
ConvertToInt32( "123456789.", provider )
ConvertToInt32( "123,456,789", provider )
ConvertToInt32( "(123456789)", provider )
ConvertToInt32( "2147483648", provider )
ConvertToInt32( "-2147483649", provider )
End Sub
End Module
' This example of
' Convert.ToInt32( String ) and
' Convert.ToInt32( String, IFormatProvider )
' generates the following output. It converts several strings to
' Integer values, using default formatting or a NumberFormatInfo object.
'
' String to convert Default/exception Provider/exception
' ----------------- ----------------- ------------------
' 123456789 123456789 123456789
' +123456789 123456789 FormatException
' pos 123456789 FormatException 123456789
' -123456789 -123456789 FormatException
' neg 123456789 FormatException -123456789
' 123456789. FormatException FormatException
' 123,456,789 FormatException FormatException
' (123456789) FormatException FormatException
' 2147483648 OverflowException OverflowException
' -2147483649 OverflowException FormatException
// Example of the Convert.ToInt32( string ) and
// Convert.ToInt32( string, IFormatProvider ) methods.
using System;
using System.Globalization;
class ToInt32ProviderDemo
{
static string format = "{0,-20}{1,-20}{2}";
// Get the exception type name; remove the namespace prefix.
static string GetExceptionType( Exception ex )
{
string exceptionType = ex.GetType( ).ToString( );
return exceptionType.Substring(
exceptionType.LastIndexOf( '.' ) + 1 );
}
static void ConvertToInt32( string numericStr,
IFormatProvider provider )
{
object defaultValue;
object providerValue;
// Convert numericStr to Int32 without a format provider.
try
{
defaultValue = Convert.ToInt32( numericStr );
}
catch( Exception ex )
{
defaultValue = GetExceptionType( ex );
}
// Convert numericStr to Int32 with a format provider.
try
{
providerValue = Convert.ToInt32( numericStr, provider );
}
catch( Exception ex )
{
providerValue = GetExceptionType( ex );
}
Console.WriteLine( format, numericStr,
defaultValue, providerValue );
}
public static void Main( )
{
// Create a NumberFormatInfo object and set several of its
// properties that apply to numbers.
NumberFormatInfo provider = new NumberFormatInfo();
// These properties affect the conversion.
provider.NegativeSign = "neg ";
provider.PositiveSign = "pos ";
// These properties do not affect the conversion.
// The input string cannot have decimal and group separators.
provider.NumberDecimalSeparator = ".";
provider.NumberGroupSeparator = ",";
provider.NumberGroupSizes = new int[ ] { 3 };
provider.NumberNegativePattern = 0;
Console.WriteLine("This example of\n" +
" Convert.ToInt32( string ) and \n" +
" Convert.ToInt32( string, IFormatProvider ) " +
"\ngenerates the following output. It converts " +
"several strings to \nint values, using " +
"default formatting or a NumberFormatInfo object.\n" );
Console.WriteLine( format, "String to convert",
"Default/exception", "Provider/exception" );
Console.WriteLine( format, "-----------------",
"-----------------", "------------------" );
// Convert strings, with and without an IFormatProvider.
ConvertToInt32( "123456789", provider );
ConvertToInt32( "+123456789", provider );
ConvertToInt32( "pos 123456789", provider );
ConvertToInt32( "-123456789", provider );
ConvertToInt32( "neg 123456789", provider );
ConvertToInt32( "123456789.", provider );
ConvertToInt32( "123,456,789", provider );
ConvertToInt32( "(123456789)", provider );
ConvertToInt32( "2147483648", provider );
ConvertToInt32( "-2147483649", provider );
}
}
/*
This example of
Convert.ToInt32( string ) and
Convert.ToInt32( string, IFormatProvider )
generates the following output. It converts several strings to
int values, using default formatting or a NumberFormatInfo object.
String to convert Default/exception Provider/exception
----------------- ----------------- ------------------
123456789 123456789 123456789
+123456789 123456789 FormatException
pos 123456789 FormatException 123456789
-123456789 -123456789 FormatException
neg 123456789 FormatException -123456789
123456789. FormatException FormatException
123,456,789 FormatException FormatException
(123456789) FormatException FormatException
2147483648 OverflowException OverflowException
-2147483649 OverflowException FormatException
*/
// Example of the Convert::ToInt32( String* ) and
// Convert::ToInt32( String*, IFormatProvider* ) methods.
using namespace System;
using namespace System::Globalization;
const __wchar_t * protoFmt = L"{0,-20}{1,-20}{2}";
// Get the exception type name; remove the namespace prefix.
String^ GetExceptionType( Exception^ ex )
{
String^ exceptionType = ex->GetType()->ToString();
return exceptionType->Substring( exceptionType->LastIndexOf( '.' ) + 1 );
}
void ConvertToInt32( String^ numericStr, IFormatProvider^ provider )
{
Object^ defaultValue;
Object^ providerValue;
// Convert numericStr to Int32 without a format provider.
try
{
defaultValue = Convert::ToInt32( numericStr );
}
catch ( Exception^ ex )
{
defaultValue = GetExceptionType( ex );
}
// Convert numericStr to Int32 with a format provider.
try
{
providerValue = Convert::ToInt32( numericStr, provider );
}
catch ( Exception^ ex )
{
providerValue = GetExceptionType( ex );
}
Console::WriteLine( gcnew String( protoFmt ), numericStr, defaultValue, providerValue );
}
int main()
{
// Create a NumberFormatInfo object and set several of its
// properties that apply to numbers.
NumberFormatInfo^ provider = gcnew NumberFormatInfo;
// These properties affect the conversion.
provider->NegativeSign = "neg ";
provider->PositiveSign = "pos ";
// These properties do not affect the conversion.
// The input string cannot have decimal and group separators.
provider->NumberDecimalSeparator = ".";
provider->NumberGroupSeparator = ",";
array<Int32>^sizes = {3};
provider->NumberGroupSizes = sizes;
provider->NumberNegativePattern = 0;
Console::WriteLine( "This example of\n"
" Convert::ToInt32( String* ) and \n"
" Convert::ToInt32( String*, IFormatProvider* ) "
"\ngenerates the following output. It converts "
"several strings to \nint values, using "
"default formatting or a NumberFormatInfo object.\n" );
Console::WriteLine( gcnew String( protoFmt ), "String to convert", "Default/exception", "Provider/exception" );
Console::WriteLine( gcnew String( protoFmt ), "-----------------", "-----------------", "------------------" );
// Convert strings, with and without an IFormatProvider.
ConvertToInt32( "123456789", provider );
ConvertToInt32( "+123456789", provider );
ConvertToInt32( "pos 123456789", provider );
ConvertToInt32( "-123456789", provider );
ConvertToInt32( "neg 123456789", provider );
ConvertToInt32( "123456789.", provider );
ConvertToInt32( "123,456,789", provider );
ConvertToInt32( "(123456789)", provider );
ConvertToInt32( "2147483648", provider );
ConvertToInt32( "-2147483649", provider );
}
/*
This example of
Convert::ToInt32( String* ) and
Convert::ToInt32( String*, IFormatProvider* )
generates the following output. It converts several strings to
int values, using default formatting or a NumberFormatInfo object.
String to convert Default/exception Provider/exception
----------------- ----------------- ------------------
123456789 123456789 123456789
+123456789 123456789 FormatException
pos 123456789 FormatException 123456789
-123456789 -123456789 FormatException
neg 123456789 FormatException -123456789
123456789. FormatException FormatException
123,456,789 FormatException FormatException
(123456789) FormatException FormatException
2147483648 OverflowException OverflowException
-2147483649 OverflowException FormatException
*/
// Example of the Convert.ToInt32( string ) and
// Convert.ToInt32( string, IFormatProvider ) methods.
import System.* ;
import System.Globalization.* ;
class ToInt32ProviderDemo
{
private static String format = "{0,-20}{1,-20}{2}";
// Get the exception type name; remove the namespace prefix.
static String GetExceptionType(System.Exception ex)
{
String exceptionType = ex.GetType().ToString();
return exceptionType.Substring((exceptionType.LastIndexOf('.') + 1)) ;
} //GetExceptionType
static void ConvertToInt32(String numericStr, IFormatProvider provider)
{
Object defaultValue;
Object providerValue;
// Convert numericStr to Int32 without a format provider.
try {
defaultValue = System.Convert.ToString(Convert.ToInt32(numericStr));
}
catch(System.Exception ex) {
defaultValue = GetExceptionType(ex);
}
// Convert numericStr to Int32 with a format provider.
try {
providerValue = System.Convert.ToString(
Convert.ToInt32(numericStr, provider));
}
catch(System.Exception ex) {
providerValue = GetExceptionType(ex);
}
Console.WriteLine(format, numericStr, defaultValue, providerValue);
} //ConvertToInt32
public static void main(String[] args)
{
// Create a NumberFormatInfo object and set several of its
// properties that apply to numbers.
NumberFormatInfo provider = new NumberFormatInfo();
// These properties affect the conversion.
provider.set_NegativeSign("neg ");
provider.set_PositiveSign("pos ");
// These properties do not affect the conversion.
// The input string cannot have decimal and group separators.
provider.set_NumberDecimalSeparator(".");
provider.set_NumberGroupSeparator(",");
provider.set_NumberGroupSizes(new int[]{3});
provider.set_NumberNegativePattern(0);
Console.WriteLine(("This example of\n"
+ " Convert.ToInt32( string ) and \n"
+ " Convert.ToInt32( string, IFormatProvider ) "
+ "\ngenerates the following output. It converts "
+ "several strings to \nint values, using "
+ "default formatting or a NumberFormatInfo object.\n"));
Console.WriteLine(format, "String to convert", "Default/exception",
"Provider/exception");
Console.WriteLine(format, "-----------------", "-----------------",
"------------------");
// Convert strings, with and without an IFormatProvider.
ConvertToInt32("123456789", provider);
ConvertToInt32("+123456789", provider);
ConvertToInt32("pos 123456789", provider);
ConvertToInt32("-123456789", provider);
ConvertToInt32("neg 123456789", provider);
ConvertToInt32("123456789.", provider);
ConvertToInt32("123,456,789", provider);
ConvertToInt32("(123456789)", provider);
ConvertToInt32("2147483648", provider);
ConvertToInt32("-2147483649", provider);
} //main
} //ToInt32ProviderDemo
/*
This example of
Convert.ToInt32( string ) and
Convert.ToInt32( string, IFormatProvider )
generates the following output. It converts several strings to
int values, using default formatting or a NumberFormatInfo object.
String to convert Default/exception Provider/exception
----------------- ----------------- ------------------
123456789 123456789 123456789
+123456789 123456789 FormatException
pos 123456789 FormatException 123456789
-123456789 -123456789 FormatException
neg 123456789 FormatException -123456789
123456789. FormatException FormatException
123,456,789 FormatException FormatException
(123456789) FormatException FormatException
2147483648 OverflowException OverflowException
-2147483649 OverflowException FormatException
*/
Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.
.NET Framework
Supported in: 2.0, 1.1, 1.0
.NET Compact Framework
Supported in: 2.0, 1.0