Int32.CompareTo方法用于将当前实例与指定的对象或Int32进行比较，并返回其相对值的符号。此方法的重载列表中有2种方法，如下所示：
- CompareTo(Int32)方法
- CompareTo(Object)方法
Int32.CompareTo(Int32)方法
此方法用于将当前实例与指定的32位带符号整数进行比较，并返回其相对值的符号。
句法：
public int CompareTo (int value);在这里，需要整数进行比较。
返回值：返回一个32位带符号的数字，指示当前实例和value参数的相对值，如下所示：
- 小于零：如果当前实例<值
- 零：如果当前实例=值
- 大于零：如果当前实例>值
下面的程序说明了上述方法的用法：
范例1：
// C# program to demonstrate the
// Int32.CompareTo(Int32) Method
using System;
class GFG {
// Main Method
public static void Main()
{
// Declaring and initializing value1
int value1 = 10;
// Declaring and initializing value2
int value2 = 20;
// using CompareTo() method
int status = value1.CompareTo(value2);
// checking the status
if (status > 0)
Console.WriteLine("{0} is greater than {1}",
value1, value2);
else if (status < 0)
Console.WriteLine("{0} is less than {1}",
value1, value2);
else
Console.WriteLine("{0} is equal to {1}",
value1, value2);
}
}
输出：
10 is less than 20
范例2：
// C# program to demonstrate the
// Int32.CompareTo(Int32) Method
using System;
class GFG {
// Main Method
public static void Main()
{
// calling get() method
get(5, 7);
get(3025, 3025);
get(10, 20);
get(7, -12);
}
// defining get() method
public static void get(int value1,
int value2)
{
// using the method
int status = value1.CompareTo(value2);
// checking the status
if (status > 0)
Console.WriteLine("{0} is greater than {1}",
value1, value2);
else if (status < 0)
Console.WriteLine("{0} is less than {1}",
value1, value2);
else
Console.WriteLine("{0} is equal to {1}",
value1, value2);
}
}
输出：
5 is less than 7
3025 is equal to 3025
10 is less than 20
7 is greater than -12
Int32.CompareTo(Object)方法
此方法用于将当前实例与指定对象进行比较，并返回其相对值的符号。
句法：
public int CompareTo (object value);在这里，它需要一个对象进行比较，或者为null。
返回值：返回一个32位带符号的数字，指示当前实例和value参数的相对值，如下所示：
- 小于零：如果当前实例<值
- 零：如果当前实例=值
- 大于零：如果当前实例> value或value为null。
异常：如果value不是Int32 ，则抛出ArgumentException 。
下面的程序说明了上述方法的用法：
范例1：
// C# program to demonstrate the
// Int32.CompareTo(Object) Method
using System;
class GFG {
// Main Method
public static void Main()
{
try {
// Declaring and initializing value1
int value1 = 10;
// Declaring and initializing value2
object value2 = 562587;
// using CompareTo() method
int status = value1.CompareTo(value2);
// checking the status
if (status > 0)
Console.WriteLine("{0} is greater than {1}",
value1, value2);
else if (status < 0)
Console.WriteLine("{0} is less than {1}",
value1, value2);
else
Console.WriteLine("{0} is equal to {1}",
value1, value2);
}
catch (ArgumentException e)
{
Console.WriteLine("value2 must be Int32");
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
}
}
输出：
10 is less than 562587
示例2：对于ArgumentException
// C# program to demonstrate the
// Int32.CompareTo(object) Method
using System;
using System.Globalization;
class GFG {
// Main Method
public static void Main()
{
try {
// Declaring and initializing value1
int value1 = 10;
// Declaring and initializing value2
object value2 = 9856745963;
// using CompareTo() method
int status = value1.CompareTo(value2);
// checking the status
if (status > 0)
Console.WriteLine("{0} is greater than {1}",
value1, value2);
else if (status < 0)
Console.WriteLine("{0} is less than {1}",
value1, value2);
else
Console.WriteLine("{0} is equal to {1}",
value1, value2);
}
catch (ArgumentException e)
{
Console.WriteLine("value2 must be Int32");
Console.Write("Exception Thrown: ");
Console.Write("{0}", e.GetType(), e.Message);
}
}
}
输出：
value2 must be Int32
Exception Thrown: System.ArgumentException
参考：
- https://docs.microsoft.com/zh-cn/dotnet/api/system.int32.compareto?view=netframework-4.7.2