System.Int32 結構

發行項
01/08/2024

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、 Double或 Decimal 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 Parse 或 TryParse 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

此 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、、 OR、 XOR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 CompareTo 或 Equals 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

此 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、標準數值格式字串和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。

共用方式為

System.Int32 結構

具現化 Int32 值

對 Int32 值執行作業

以字串表示 Int32

使用非十進位32位整數值

其他資源