Double.Equals()方法用于获取一个值，该值指示Double的两个实例是否表示相同的值。此方法的重载列表中共有两种方法，如下所示：
- 等于(双精度)方法
- 等于(对象)方法
Double.Equals(Double)
此方法用于返回一个值，该值指示此实例和指定的Double对象是否表示相同的值。
Syntax: public bool Equals (double obj);
Here, it takes a Double object to compare to this instance.
Return Value: This method returns true if obj is equal to this instance; otherwise, false.
下面的程序说明Double.Equals()方法的用法：
范例1：
// C# program to demonstrate the
// Double.Equals(Double)
// Method
using System;
using System.Globalization;
class GFG {
// Main Method
public static void Main()
{
// Declaring and initializing value1
double value1 = 10d;
// Declaring and initializing value2
double value2 = 20d;
// compare both double value
// using Equals(Double) method
bool status = value1.Equals(value2);
// checking the status
if (status)
Console.WriteLine("{0} is equal to {1}",
value1, value2);
else
Console.WriteLine("{0} is not equal to {1}",
value1, value2);
}
}
输出：
10 is not equal to 20
范例2：
// C# program to demonstrate the
// Double.Equals(Double)
// Method
using System;
using System.Globalization;
class GFG {
// Main Method
public static void Main()
{
// calling get() method
get(5d, 5d);
get(5.5d, 4.5d);
get(10d, 20d);
get(7.5d, 19.5d);
}
// defining get() method
public static void get(double value1, double value2)
{
// compare both double value
// using Equals(Double) method
bool status = value1.Equals(value2);
// cheking the status
if (status)
Console.WriteLine("{0} is equal to {1}",
value1, value2);
else
Console.WriteLine("{0} is not equal to {1}",
value1, value2);
}
}
输出：
5 is equal to 5
5.5 is not equal to 4.5
10 is not equal to 20
7.5 is not equal to 19.5
Double.Equals(Object)方法
此方法用于返回一个值，该值指示此实例是否等于指定的对象。
Syntax: public override bool Equals (object obj);
Here, it takes an object to compare with this instance.
Return Value: This method returns true if obj is an instance of Double and equals the value of this instance; otherwise, false.
下面的程序说明了上述方法的用法：
范例1：
// C# program to demonstrate the
// Double.Equals(Object)
// Method
using System;
using System.Globalization;
class GFG {
// Main Method
public static void Main()
{
// Declaring and initializing value1
double value1 = 10d;
// Declaring and initializing value2
object value2 = 1 / 36;
// compare both double value
// using Equals(object) method
bool status = value1.Equals(value2);
// checking the status
if (status)
Console.WriteLine("{0} is equal to {1}",
value1, value2);
else
Console.WriteLine("{0} is not equal to {1}",
value1, value2);
}
}
输出：
10 is not equal to 0
范例2：
// C# program to demonstrate the
// Double.Equals(object)
// Method
using System;
using System.Globalization;
class GFG {
// Main Method
public static void Main()
{
// calling get() method
get(5d, 1 / 3);
get(5.5d, 1 / 3);
get(10d, 1 / 24);
get(7.5d, 2 / 5);
}
// defining get() method
public static void get(double value1, object value2)
{
// compare both double value
// using Equals(object) method
bool status = value1.Equals(value2);
// checking the status
if (status)
Console.WriteLine("{0} is equal to {1}",
value1, value2);
else
Console.WriteLine("{0} is not equal to {1}",
value1, value2);
}
}
输出：
5 is not equal to 0
5.5 is not equal to 0
10 is not equal to 0
7.5 is not equal to 0
参考：
- https://docs.microsoft.com/zh-cn/dotnet/api/system.double.equals?view=netframework-4.7.2