Convertとは？ わかりやすく解説

Public NotInheritable Class
 Convert

Dim instance As Convert

public sealed class Convert

public ref class Convert sealed

public final class Convert

public final class Convert

Public NotInheritable Class
 Convert

静的クラスのメンバは、クラスのインスタンスなしに直接アクセスされます。

public static class Convert

public ref class Convert abstract sealed

public final class Convert

public final class Convert

Dim dNumber As Double
dNumber = 23.15

Try
   ' Returns 23
   Dim iNumber As Integer
   iNumber = System.Convert.ToInt32(dNumber)
Catch exp As System.OverflowException
   System.Console.WriteLine("Overflow in double to int conversion.")
End Try

' Returns True
Dim bNumber As Boolean
bNumber = System.Convert.ToBoolean(dNumber)

' Returns "23.15"
Dim strNumber As String
strNumber = System.Convert.ToString(dNumber)

Try
   ' Returns '2'
   Dim chrNumber As Char
   chrNumber = System.Convert.ToChar(strNumber.Chars(1))
Catch exp As System.ArgumentNullException
   System.Console.WriteLine("String is null.")
Catch exp As System.FormatException
   System.Console.WriteLine("String length is greater than 1.")
End Try

' System.Console.ReadLine() returns a string and it
' must be converted.
Dim newInteger As Integer
newInteger = 0
Try
   System.Console.WriteLine("Enter an integer:")
   newInteger = System.Convert.ToInt32(System.Console.ReadLine())
Catch exp As System.ArgumentNullException
   System.Console.WriteLine("String is null.")
Catch exp As System.FormatException
   System.Console.WriteLine("String does not consist of an "
 + _
       "optional sign followed by a series of digits.")
Catch exp As System.OverflowException
   System.Console.WriteLine("Overflow in string to int conversion.")
End Try

System.Console.WriteLine("Your integer as a double is {0}",
 _
                         System.Convert.ToDouble(newInteger))

double dNumber = 23.15;

try {
    // Returns 23
    int    iNumber = System.Convert.ToInt32(dNumber);
}
catch (System.OverflowException) {
    System.Console.WriteLine(
                "Overflow in double to int
 conversion.");
}
// Returns True
bool   bNumber = System.Convert.ToBoolean(dNumber);

// Returns "23.15"
string strNumber = System.Convert.ToString(dNumber);

try {
    // Returns '2'
    char chrNumber = System.Convert.ToChar(strNumber[0]);
} 
catch (System.ArgumentNullException) {
    System.Console.WriteLine("String is null");
}
catch (System.FormatException) {
    System.Console.WriteLine("String length is greater than 1.");
}

// System.Console.ReadLine() returns a string and it
// must be converted.
int newInteger = 0;
try {
    System.Console.WriteLine("Enter an integer:");
    newInteger = System.Convert.ToInt32(
                        System.Console.ReadLine());
}
catch (System.ArgumentNullException) {
    System.Console.WriteLine("String is null.");
}
catch (System.FormatException) {
    System.Console.WriteLine("String does not consist of an " +
                    "optional sign followed by a series of digits.");
} 
catch (System.OverflowException) {
    System.Console.WriteLine(
    "Overflow in string to int
 conversion.");
}

System.Console.WriteLine("Your integer as a double is {0}",
                         System.Convert.ToDouble(newInteger));

Double dNumber = 23.15;

try
{
   // Returns 23
   Int32 iNumber = Convert::ToInt32( dNumber );
}
catch ( OverflowException^ ) 
{
   Console::WriteLine(
      "Overflow in Double to Int32 conversion" );
}
// Returns True
Boolean bNumber = Convert::ToBoolean( dNumber );

// Returns "23.15"
String^ strNumber = Convert::ToString( dNumber );

try
{
   // Returns '2'
   Char chrNumber = Convert::ToChar( strNumber->Substring( 0, 1 ) );
}
catch ( ArgumentNullException^ ) 
{
   Console::WriteLine(  "String is null" );
}
catch ( FormatException^ ) 
{
   Console::WriteLine(  "String length is greater than 1" );
}

// System::Console::ReadLine() returns a string and it
// must be converted.
Int32 newInteger = 0;
try
{
   Console::WriteLine(  "Enter an integer:" );
   newInteger = Convert::ToInt32( System::Console::ReadLine() );
}
catch ( ArgumentNullException^ ) 
{
   Console::WriteLine(  "String is null" );
}
catch ( FormatException^ ) 
{
   Console::WriteLine(  "String does not consist of an " +
      "optional sign followed by a series of digits" );
}
catch ( OverflowException^ ) 
{
   Console::WriteLine(  "Overflow in string
 to Int32 conversion" );
}

Console::WriteLine( "Your integer as a Double is {0}",
   Convert::ToDouble( newInteger ) );

double dNumber = 23.15;

try {        
    // Returns 23
    int iNumber = System.Convert.ToInt32(dNumber);
}
catch (System.OverflowException exp) {        
    System.Console.WriteLine("Overflow in double to int
 conversion.");
}

// Returns True
boolean bNumber = System.Convert.ToBoolean(dNumber);

// Returns "23.15"
String strNumber = System.Convert.ToString(dNumber);

try {        
    // Returns '2'
    char chrNumber = System.Convert.ToChar(strNumber.get_Chars(0));
}
catch (System.ArgumentNullException exp) {        
    System.Console.WriteLine("String is null");
}
catch (System.FormatException exp) {        
    System.Console.WriteLine("String length is greater than 1.");
}

// System.Console.ReadLine() returns a string and it
// must be converted.
int newInteger = 0;

try {        
    System.Console.WriteLine("Enter an integer:");
    newInteger = System.Convert.ToInt32(System.Console.ReadLine());
}
catch (System.ArgumentNullException exp) {        
    System.Console.WriteLine("String is null.");
}
catch (System.FormatException exp) {        
    System.Console.WriteLine(("String does not consist of an " 
        + "optional sign followed by a series of digits."));
}
catch (System.OverflowException exp) {        
    System.Console.WriteLine("Overflow in string
 to int conversion.");
}
System.Console.WriteLine("Your integer as a double is {0}", 
    System.Convert.ToString(System.Convert.ToDouble(newInteger)));

' Sample for the Convert class summary.
Imports System

Class Sample
   Public Shared Sub Main()
      Dim nl As String =
 Environment.NewLine
      Dim str As String
 = "{0}Return the Int64 equivalent of the following base types:{0}"
      Dim xBool As Boolean
 = False
      Dim xShort As Short
 = 1
      Dim xInt As Integer
 = 2
      Dim xLong As Long
 = 3
      Dim xSingle As Single
 = 4F
      Dim xDouble As Double
 = 5.0
      Dim xDecimal As Decimal
 = 6D
      Dim xString As String
 = "7"
      Dim xChar As Char
 = "8"c ' '8' = hexadecimal 38 = decimal
 56
      Dim xByte As Byte
 = 9
      
      '  The following types are not CLS-compliant.
      ' Dim xUshort As System.UInt16 = 120
      ' Dim xUint As System.UInt32 = 121
      ' Dim xUlong As System.UInt64 = 122
      ' Dim xSbyte As System.SByte = 123
      
      '  The following type cannot be converted to an Int64.
      '  Dim xDateTime As System.DateTime = DateTime.Now

      Console.WriteLine(str, nl)
      Console.WriteLine("Boolean:  {0}", Convert.ToInt64(xBool))
      Console.WriteLine("Int16:    {0}", Convert.ToInt64(xShort))
      Console.WriteLine("Int32:    {0}", Convert.ToInt64(xInt))
      Console.WriteLine("Int64:    {0}", Convert.ToInt64(xLong))
      Console.WriteLine("Single:   {0}", Convert.ToInt64(xSingle))
      Console.WriteLine("Double:   {0}", Convert.ToInt64(xDouble))
      Console.WriteLine("Decimal:  {0}", Convert.ToInt64(xDecimal))
      Console.WriteLine("String:   {0}", Convert.ToInt64(xString))
      Console.WriteLine("Char:     {0}", Convert.ToInt64(xChar))
      Console.WriteLine("Byte:     {0}", Convert.ToInt64(xByte))
      Console.WriteLine("DateTime: There is no example of this
 conversion because")
      Console.WriteLine("          a DateTime cannot be converted
 to an Int64.")
      '
      Console.Write("{0}The following types are not supported:
 ", nl)
      Console.WriteLine("UInt16, UInt32, UInt64, and SByte")
   End Sub 'Main
End Class 'Sample
'
'This example produces the following results:
'
'Return the Int64 equivalent of the following base types:
'
'Boolean:  0
'Int16:    1
'Int32:    2
'Int64:    3
'Single:   4
'Double:   5
'Decimal:  6
'String:   7
'Char:     56
'Byte:     9
'DateTime: There is no example of this conversion because
'          a DateTime cannot be converted to an Int64.
'
'The following types are not supported: UInt16, UInt32, UInt64, and
 SByte
'

// Sample for the Convert class summary.
using System;

class Sample 
{
    public static void Main()
 
    {
    string nl = Environment.NewLine;
    string str = "{0}Return the Int64 equivalent of the following
 base types:{0}";
    bool    xBool = false;
    short   xShort = 1;
    int     xInt   = 2;
    long    xLong  = 3;
    float   xSingle = 4.0f;
    double  xDouble = 5.0;
    decimal xDecimal = 6.0m;
    string  xString = "7";
    char    xChar   = '8'; // '8' = hexadecimal 38
 = decimal 56
    byte    xByte  =  9;

//  The following types are not CLS-compliant.
    ushort  xUshort = 120;   
    uint    xUint =   121;
    ulong   xUlong =  122;
    sbyte   xSbyte  = 123;

//  The following type cannot be converted to an Int64.
//  DateTime xDateTime = DateTime.Now;

    Console.WriteLine(str, nl);
    Console.WriteLine("Boolean:  {0}", Convert.ToInt64(xBool));
    Console.WriteLine("Int16:    {0}", Convert.ToInt64(xShort));
    Console.WriteLine("Int32:    {0}", Convert.ToInt64(xInt));
    Console.WriteLine("Int64:    {0}", Convert.ToInt64(xLong));
    Console.WriteLine("Single:   {0}", Convert.ToInt64(xSingle));
    Console.WriteLine("Double:   {0}", Convert.ToInt64(xDouble));
    Console.WriteLine("Decimal:  {0}", Convert.ToInt64(xDecimal));
    Console.WriteLine("String:   {0}", Convert.ToInt64(xString));
    Console.WriteLine("Char:     {0}", Convert.ToInt64(xChar));
    Console.WriteLine("Byte:     {0}", Convert.ToInt64(xByte));
    Console.WriteLine("DateTime: There is no example of this
 conversion because");
    Console.WriteLine("          a DateTime cannot be converted to an Int64.");
//
    Console.WriteLine("{0}The following types are not CLS-compliant.{0}",
 nl);
    Console.WriteLine("UInt16:   {0}", Convert.ToInt64(xUshort));
    Console.WriteLine("UInt32:   {0}", Convert.ToInt64(xUint));
    Console.WriteLine("UInt64:   {0}", Convert.ToInt64(xUlong));
    Console.WriteLine("SByte:    {0}", Convert.ToInt64(xSbyte));
    }
}
/*
This example produces the following results:

Return the Int64 equivalent of the following base types:

Boolean:  0
Int16:    1
Int32:    2
Int64:    3
Single:   4
Double:   5
Decimal:  6
String:   7
Char:     56
Byte:     9
DateTime: There is no example of this conversion because
          a DateTime cannot be converted to an Int64.

The following types are not CLS-compliant.

UInt16:   120
UInt32:   121
UInt64:   122
SByte:    123
*/

// Sample for the Convert class summary.
using namespace System;
int main()
{
   String^ nl = Environment::NewLine;
   String^ str = " {0}Return the Int64 equivalent of the following base
 types: {0}";
   bool xBool = false;
   short xShort = 1;
   int xInt = 2;
   long xLong = 3;
   float xSingle = 4.0f;
   double xDouble = 5.0;
   Decimal xDecimal = Decimal(6.0);
   String^ xString = "7";
   char xChar = '8'; // '8' = hexadecimal 38 = decimal
 56

   Byte xByte = 9;
   
   //  The following types are not CLS-compliant.
   UInt16 xUshort = 120;
   UInt32 xUint = 121;
   UInt64 xUlong = 122;
   SByte xSbyte = 123;
   
   //  The following type cannot be converted to an Int64.
   //  DateTime xDateTime = DateTime::Now;
   Console::WriteLine( str, nl );
   Console::WriteLine( "Boolean: {0}", Convert::ToInt64( xBool ) );
   Console::WriteLine( "Int16: {0}", Convert::ToInt64( xShort ) );
   Console::WriteLine( "Int32: {0}", Convert::ToInt64( xInt ) );
   Console::WriteLine( "Int64: {0}", Convert::ToInt64( xLong ) );
   Console::WriteLine( "Single: {0}", Convert::ToInt64( xSingle ) );
   Console::WriteLine( "Double: {0}", Convert::ToInt64( xDouble ) );
   Console::WriteLine( "Decimal: {0}", Convert::ToInt64( xDecimal ) );
   Console::WriteLine( "String: {0}", Convert::ToInt64( xString ) );
   Console::WriteLine( "Char: {0}", Convert::ToInt64( xChar ) );
   Console::WriteLine( "Byte: {0}", Convert::ToInt64( xByte ) );
   Console::WriteLine( "DateTime: There is no example of this
 conversion because" );
   Console::WriteLine( "          a DateTime cannot be converted to an Int64."
 );
   
   //
   Console::WriteLine( " {0}The following types are not CLS-compliant. {0}",
 nl );
   Console::WriteLine( "UInt16: {0}", Convert::ToInt64( xUshort ) );
   Console::WriteLine( "UInt32: {0}", Convert::ToInt64( xUint ) );
   Console::WriteLine( "UInt64: {0}", Convert::ToInt64( xUlong ) );
   Console::WriteLine( "SByte: {0}", Convert::ToInt64( xSbyte ) );
}

/*
This example produces the following results:

Return the Int64 equivalent of the following base types:

Boolean:  0
Int16:    1
Int32:    2
Int64:    3
Single:   4
Double:   5
Decimal:  6
String:   7
Char:     56
Byte:     9
DateTime: There is no example of this conversion because
a DateTime cannot be converted to an Int64.

The following types are not CLS-compliant.

UInt16:   120
UInt32:   121
UInt64:   122
SByte:    123
*/

Public Sub New

Dim instance As New Convert

public Convert ()

public:
Convert ()

public Convert ()

public function Convert ()