雙類compareTo()方法 (Double class compareTo() method)

• compareTo() method is available in java.lang package.

  compareTo()方法在java.lang包中可用。

• compareTo() method is used to check equality or inequality for this Double-object against the given Double-object mathematically or in other words, we can say this method is used to compare two Double objects.

  compareTo()方法用于在數學上檢查該Double對象與給定Double對象的相等性或不相等性，換句話說，可以說此方法用于比較兩個Double對象。

• compareTo() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.

  compareTo()方法是一種非靜態方法，只能通過類對象訪問，如果嘗試使用類名稱訪問該方法，則會收到錯誤消息。

• compareTo() method does not throw an exception at the time of comparing Double-object.

  在比較Double-object時， compareTo()方法不會引發異常。

Syntax:

句法：

    public int compareTo(Double value2);

Parameter(s):

參數：

• Double value2 – represents the Double object to compare with.

  Double value2-表示要比較的Double對象。

Return value:

返回值：

The return type of this method is int, it returns an integer value. It returns 0 if value2 is mathematically equal to value1 (this object), it returns value < 0 if value2 is mathematically greater than value1 (this object), it returns value > 0 if value2 is mathematically less than value1 (this object).

此方法的返回類型為int ，它返回一個整數值。 它返回0，如果值2是數學上等于值1(該對象)，則返回值<0，如果是數值2比數學VALUE1(此對象)時，它返回值> 0，如果值2小于值1數學上更小(該對象)。

Example:

例：

// Java program to demonstrate the example 
// of compareTo(Double value2) method of Double class
public class CompareToOfDoubleClass {
public static void main(String[] args) {
// Variables initialization
double d1 = 18.20;
double d2 = 20.20;
// Double instance 
Double value1 = new Double(d1);
Double value2 = new Double(d2);
// It compare two Double objects and placed the 
// result in another variable (compare) of integer type
int compare = value1.compareTo(value2);
// Display result
System.out.println("value1.compareTo(value2): " + compare);
System.out.println();
if (compare == 0)
System.out.println("value1 is equal to value2");
else if (compare < 0)
System.out.println("value1 is less than value2");
else
System.out.println("value1 is greater than value2");
}
}

Output

輸出量

value1.compareTo(value2): -1value1 is less than value2

翻譯自: https://www.includehelp.com/java/double-class-compareto-method-with-example.aspx