共用方式為


System.Int32 結構

本文提供此 API 參考文件的補充備註。

Int32 是不可變的實值型別,表示帶正負數 2,147,483,648(以常數表示 Int32.MinValue )到正 2,147,483,647(以常數表示 Int32.MaxValue )的帶正整數。 .NET 也包含不帶正負號的 32 位整數實值型別, UInt32代表範圍從 0 到 4,294,967,295 的值。

具現化 Int32 值

您可以透過數種方式具現化 Int32 值:

  • 您可以宣告 Int32 變數,併為其指派數據類型範圍內的 Int32 常值整數值。 下列範例會宣告兩個 Int32 變數,並以這種方式指派這些變數。

    int number1 = 64301;
    int number2 = 25548612;
    
    let number1 = 64301
    let number2 = 25548612
    
    Dim number1 As Integer = 64301
    Dim number2 As Integer = 25548612
    
  • 您可以指派整數型別的值,其範圍是型別 Int32 的子集。 這是擴大轉換,不需要 C# 中的轉換運算元或 Visual Basic 中的轉換方法,但在 F# 中則需要轉換運算元。

    sbyte value1 = 124;
    short value2 = 1618;
    
    int number1 = value1;
    int number2 = value2;
    
    let value1 = 124y
    let value2 = 1618s
    
    let number1 = int value1
    let number2 = int value2
    
    Dim value1 As SByte = 124
    Dim value2 As Int16 = 1618
    
    Dim number1 As Integer = value1
    Dim number2 As Integer = value2
    
  • 您可以指派數值型別的值,其範圍超過該型別的值 Int32 。 這是縮小轉換,因此它需要 C# 或 F# 中的轉換運算符,並在 Visual Basic 中開啟 Option Strict 轉換方法。 如果數值是包含 Single小數位元件的、 DoubleDecimal 值,則其小數部分的處理取決於執行轉換的編譯程式。 下列範例會執行縮小轉換,將數個數值指派給 Int32 變數。

    long lNumber = 163245617;
    try {
       int number1 = (int) lNumber;
       Console.WriteLine(number1);
    }
    catch (OverflowException) {
       Console.WriteLine("{0} is out of range of an Int32.", lNumber);
    }
    
    double dbl2 = 35901.997;
    try {
       int number2 = (int) dbl2;
       Console.WriteLine(number2);
    }
    catch (OverflowException) {
       Console.WriteLine("{0} is out of range of an Int32.", dbl2);
    }
    
    BigInteger bigNumber = 132451;
    try {
       int number3 = (int) bigNumber;
       Console.WriteLine(number3);
    }
    catch (OverflowException) {
       Console.WriteLine("{0} is out of range of an Int32.", bigNumber);
    }
    // The example displays the following output:
    //       163245617
    //       35902
    //       132451
    
    let lNumber = 163245617L
    try
        let number1 = int lNumber
        printfn $"{number1}"
    with :? OverflowException ->
        printfn "{lNumber} is out of range of an Int32."
    
    let dbl2 = 35901.997
    try
        let number2 = int dbl2
        printfn $"{number2}"
    with :? OverflowException ->
        printfn $"{dbl2} is out of range of an Int32."
    
    let bigNumber = BigInteger 132451
    try
        let number3 = int bigNumber
        printfn $"{number3}"
    with :? OverflowException ->
        printfn $"{bigNumber} is out of range of an Int32."
    
    // The example displays the following output:
    //       163245617
    //       35902
    //       132451
    
    Dim lNumber As Long = 163245617
    Try
       Dim number1 As Integer = CInt(lNumber)
       Console.WriteLine(number1)
    Catch e As OverflowException
       Console.WriteLine("{0} is out of range of an Int32.", lNumber)
    End Try
    
    Dim dbl2 As Double = 35901.997
    Try
       Dim number2 As Integer = CInt(dbl2)
       Console.WriteLine(number2)
    Catch e As OverflowException
       Console.WriteLine("{0} is out of range of an Int32.", dbl2)
    End Try
       
    Dim bigNumber As BigInteger = 132451
    Try
       Dim number3 As Integer = CInt(bigNumber)
       Console.WriteLine(number3)
    Catch e As OverflowException
       Console.WriteLine("{0} is out of range of an Int32.", bigNumber)
    End Try    
    ' The example displays the following output:
    '       163245617
    '       35902
    '       132451
    
  • 您可以呼叫 類別的 Convert 方法,將任何支援的型 Int32 別轉換為值。 這是可能的,因為 Int32 支援 IConvertible 介面。 下列範例說明如何將值Int32陣列Decimal轉換成值。

    decimal[] values= { Decimal.MinValue, -1034.23m, -12m, 0m, 147m,
                        199.55m, 9214.16m, Decimal.MaxValue };
    int result;
    
    foreach (decimal 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);
       }
    }
    // The example displays the following output:
    //    -79228162514264337593543950335 is outside the range of the Int32 type.
    //    Converted the Decimal value '-1034.23' to the Int32 value -1034.
    //    Converted the Decimal value '-12' to the Int32 value -12.
    //    Converted the Decimal value '0' to the Int32 value 0.
    //    Converted the Decimal value '147' to the Int32 value 147.
    //    Converted the Decimal value '199.55' to the Int32 value 200.
    //    Converted the Decimal value '9214.16' to the Int32 value 9214.
    //    79228162514264337593543950335 is outside the range of the Int32 type.
    
    let values = 
        [| Decimal.MinValue; -1034.23M; -12m; 0M; 147M
           199.55M; 9214.16M; Decimal.MaxValue |]
    
    for value in values do
        try
            let result = Convert.ToInt32 value
            printfn $"Converted the {value.GetType().Name} value '{value}' to the {result.GetType().Name} value {result}."
            
        with :? OverflowException ->
            printfn $"{value} is outside the range of the Int32 type."
       
    // The example displays the following output:
    //    -79228162514264337593543950335 is outside the range of the Int32 type.
    //    Converted the Decimal value '-1034.23' to the Int32 value -1034.
    //    Converted the Decimal value '-12' to the Int32 value -12.
    //    Converted the Decimal value '0' to the Int32 value 0.
    //    Converted the Decimal value '147' to the Int32 value 147.
    //    Converted the Decimal value '199.55' to the Int32 value 200.
    //    Converted the Decimal value '9214.16' to the Int32 value 9214.
    //    79228162514264337593543950335 is outside the range of the Int32 type.
    
    Dim values() As Decimal = { Decimal.MinValue, -1034.23d, -12d, 0d, 147d, _
                                199.55d, 9214.16d, Decimal.MaxValue }
    Dim result As Integer
    
    For Each value As Decimal 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 e As OverflowException
          Console.WriteLine("{0} is outside the range of the Int32 type.", _
                            value)
       End Try   
    Next                                  
    ' The example displays the following output:
    '    -79228162514264337593543950335 is outside the range of the Int32 type.
    '    Converted the Decimal value '-1034.23' to the Int32 value -1034.
    '    Converted the Decimal value '-12' to the Int32 value -12.
    '    Converted the Decimal value '0' to the Int32 value 0.
    '    Converted the Decimal value '147' to the Int32 value 147.
    '    Converted the Decimal value '199.55' to the Int32 value 200.
    '    Converted the Decimal value '9214.16' to the Int32 value 9214.
    '    79228162514264337593543950335 is outside the range of the Int32 type.
    
  • 您可以呼叫 ParseTryParse 方法,將值的字串表示 Int32 轉換成 Int32。 字串可以包含十進位或十六進位數位。 下列範例說明使用十進位和十六進位字串來剖析作業。

    string string1 = "244681";
    try {
       int number1 = Int32.Parse(string1);
       Console.WriteLine(number1);
    }
    catch (OverflowException) {
       Console.WriteLine("'{0}' is out of range of a 32-bit integer.", string1);
    }
    catch (FormatException) {
       Console.WriteLine("The format of '{0}' is invalid.", string1);
    }
    
    string string2 = "F9A3C";
    try {
       int number2 = Int32.Parse(string2,
                                System.Globalization.NumberStyles.HexNumber);
       Console.WriteLine(number2);
    }
    catch (OverflowException) {
       Console.WriteLine("'{0}' is out of range of a 32-bit integer.", string2);
    }
    catch (FormatException) {
       Console.WriteLine("The format of '{0}' is invalid.", string2);
    }
    // The example displays the following output:
    //       244681
    //       1022524
    
    let string1 = "244681"
    try
        let number1 = Int32.Parse string1
        printfn $"{number1}"
    with
    | :? OverflowException ->
        printfn "'{string1}' is out of range of a 32-bit integer."
    | :? FormatException ->
        printfn $"The format of '{string1}' is invalid."
    
    let string2 = "F9A3C"
    try
        let number2 = Int32.Parse(string2, System.Globalization.NumberStyles.HexNumber)
        printfn $"{number2}"
    with 
    | :? OverflowException ->
        printfn $"'{string2}' is out of range of a 32-bit integer."
    | :? FormatException ->
        printfn $"The format of '{string2}' is invalid."
    
    // The example displays the following output:
    //       244681
    //       1022524
    
    Dim string1 As String = "244681"
    Try
       Dim number1 As Integer = Int32.Parse(string1)
       Console.WriteLine(number1)
    Catch e As OverflowException
       Console.WriteLine("'{0}' is out of range of a 32-bit integer.", string1)
    Catch e As FormatException
       Console.WriteLine("The format of '{0}' is invalid.", string1)
    End Try
    
    Dim string2 As String = "F9A3C"
    Try
       Dim number2 As Integer = Int32.Parse(string2,
                                System.Globalization.NumberStyles.HexNumber)
       Console.WriteLine(number2)
    Catch e As OverflowException
       Console.WriteLine("'{0}' is out of range of a 32-bit integer.", string2)
    Catch e As FormatException
       Console.WriteLine("The format of '{0}' is invalid.", string2)
    End Try
    ' The example displays the following output:
    '       244681
    '       1022524
    

對 Int32 值執行作業

Int32 類型支援標準數學運算,例如加法、減法、除法、乘法、否定和一元否定。 如同其他整數型別,此 Int32 類型也支援位 AND、、 ORXOR左移和右移運算符。

您可以使用標準數值運算符來比較兩個 Int32 值,也可以呼叫 CompareToEquals 方法。

您也可以呼叫 類別的成員 Math 來執行廣泛的數值運算,包括取得數字的絕對值、計算整數除數的商數和餘數、判斷兩個整數的最大值或最小值、取得數位的正負號,以及四捨五入數位。

以字串表示 Int32

Int32 類型提供標準和自定義數值格式字串的完整支援。 (如需詳細資訊,請參閱 格式化類型標準數值格式字串自定義數值格式字串。)

若要將 Int32 值格式化為不含前置零的整數位符串,您可以呼叫無 ToString() 參數方法。 藉由使用 「D」 格式規範,您也可以在字串表示中包含指定數目的前置零。 藉由使用 「N」 格式規範,您可以包含群組分隔符,並指定要出現在數位字串表示中的十進位數。 藉由使用 「X」 格式規範,您可以將值表示 Int32 為十六進位字串。 下列範例會以這四種方式格式化值陣列 Int32 中的元素。

int[] numbers = { -1403, 0, 169, 1483104 };
foreach (int number in numbers)
{
    // Display value using default formatting.
    Console.Write("{0,-8}  -->   ", number.ToString());
    // Display value with 3 digits and leading zeros.
    Console.Write("{0,11:D3}", number);
    // Display value with 1 decimal digit.
    Console.Write("{0,13:N1}", number);
    // Display value as hexadecimal.
    Console.Write("{0,12:X2}", number);
    // Display value with eight hexadecimal digits.
    Console.WriteLine("{0,14:X8}", number);
}
// The example displays the following output:
//    -1403     -->         -1403     -1,403.0    FFFFFA85      FFFFFA85
//    0         -->           000          0.0          00      00000000
//    169       -->           169        169.0          A9      000000A9
//    1483104   -->       1483104  1,483,104.0      16A160      0016A160
let numbers = [| -1403; 0; 169; 1483104 |]
for number in numbers do
    // Display value using default formatting.
    printf $"{number,-8}  -->   "
    // Display value with 3 digits and leading zeros.
    printf $"{number,11:D3}"
    // Display value with 1 decimal digit.
    printf $"{number,13:N1}"
    // Display value as hexadecimal.
    printf $"{number,12:X2}"
    // Display value with eight hexadecimal digits.
    printfn $"{number,14:X8}"


  // The example displays the following output:
  //    -1403     -->         -1403     -1,403.0    FFFFFA85      FFFFFA85
  //    0         -->           000          0.0          00      00000000
  //    169       -->           169        169.0          A9      000000A9
  //    1483104   -->       1483104  1,483,104.0      16A160      0016A160
Dim numbers() As Integer = { -1403, 0, 169, 1483104 }
For Each number As Integer In numbers
   ' Display value using default formatting.
   Console.Write("{0,-8}  -->   ", number.ToString())
   ' Display value with 3 digits and leading zeros.
   Console.Write("{0,11:D3}", number) 
   ' Display value with 1 decimal digit.
   Console.Write("{0,13:N1}", number) 
   ' Display value as hexadecimal.
   Console.Write("{0,12:X2}", number) 
   ' Display value with eight hexadecimal digits.
   Console.WriteLine("{0,14:X8}", number)
Next   
' The example displays the following output:
'    -1403     -->         -1403     -1,403.0    FFFFFA85      FFFFFA85
'    0         -->           000          0.0          00      00000000
'    169       -->           169        169.0          A9      000000A9
'    1483104   -->       1483104  1,483,104.0      16A160      0016A160

您也可以呼叫 ToString(Int32, Int32) 方法,並提供基底做為方法的第二個參數,將值格式化Int32為二進位、八進位、十六進位或十六進位字串。 下列範例會呼叫這個方法,以顯示整數值陣列的二進位、八進位和十六進位表示法。

int[] numbers = { -146, 11043, 2781913 };
Console.WriteLine("{0,8}   {1,32}   {2,11}   {3,10}",
                  "Value", "Binary", "Octal", "Hex");
foreach (int number in numbers)
{
    Console.WriteLine("{0,8}   {1,32}   {2,11}   {3,10}",
                      number, Convert.ToString(number, 2),
                      Convert.ToString(number, 8),
                      Convert.ToString(number, 16));
}
// The example displays the following output:
//       Value                             Binary         Octal          Hex
//        -146   11111111111111111111111101101110   37777777556     ffffff6e
//       11043                     10101100100011         25443         2b23
//     2781913             1010100111001011011001      12471331       2a72d9
let numbers = [| -146; 11043; 2781913 |]
printfn $"""{"Value",8}   {"Binary",32}   {"Octal",11}   {"Hex",10}""" 
for number in numbers do
    printfn $"{number,8}   {Convert.ToString(number, 2),32}   {Convert.ToString(number, 8),11}   {Convert.ToString(number, 16),10}"

// The example displays the following output:
//       Value                             Binary         Octal          Hex
//        -146   11111111111111111111111101101110   37777777556     ffffff6e
//       11043                     10101100100011         25443         2b23
//     2781913             1010100111001011011001      12471331       2a72d9
Dim numbers() As Integer = { -146, 11043, 2781913 }
Console.WriteLine("{0,8}   {1,32}   {2,11}   {3,10}", _
                  "Value", "Binary", "Octal", "Hex")
For Each number As Integer In numbers
   Console.WriteLine("{0,8}   {1,32}   {2,11}   {3,10}", _
                     number, Convert.ToString(number, 2), _
                     Convert.ToString(number, 8), _
                     Convert.ToString(number, 16))
Next      
' The example displays the following output:
'       Value                             Binary         Octal          Hex
'        -146   11111111111111111111111101101110   37777777556     ffffff6e
'       11043                     10101100100011         25443         2b23
'     2781913             1010100111001011011001      12471331       2a72d9

使用非十進位32位整數值

除了使用個別整數做為十進位值之外,您可能還想要使用整數值執行位運算,或是使用整數值的二進位或十六進位表示法。 Int32 值以 31 位表示,而使用 31 秒位做為符號位。 正值是使用正負號表示法來表示。 負值在兩者的補碼表示法中。 當您對 Int32 值執行位運算或處理個別位時,請務必記住這點。 若要在任何兩個非十進位值上執行數值、布爾值或比較運算,這兩個值都必須使用相同的表示法。