Java OptionalDouble equals()用法及代码示例

OptionalDouble帮助我们创建一个可能包含或可能不包含Double值的对象。 equals(Object obj)方法可帮助我们将此OptionalDouble对象与传递的对象作为参数进行比较，如果对象相等，则返回true。

如果满足以下条件，则认为另一个对象与此OptionalDouble相等：

它也是一个OptionalDouble和;
两个实例都不存在值；或者
当前值通过==彼此为“equal to”。

用法:

public boolean equals(Object obj)

参数：此方法接受obj，它是要测试是否相等的对象。

返回值：如果另一个对象是“equal to”，则此方法返回true；否则返回false。

以下示例程序旨在说明equals(Object obj)方法：

示例1:

// Java program to demonstrate 
// OptionalDouble.equals(Object obj) method 
  
import java.util.OptionalDouble; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
  
        // Create first OptionalDouble object 
        OptionalDouble opDouble1 
            = OptionalDouble.of(452.13246); 
  
        System.out.println("OptionalDouble 1: "
                           + opDouble1.toString()); 
  
        // Create second OptionalDouble object 
        OptionalDouble opDouble2 
            = OptionalDouble.of(452.13246); 
  
        System.out.println("OptionalDouble 2: "
                           + opDouble2.toString()); 
  
        // Check if these two objects are equal 
        // using equals(Object obj) 
        System.out.println("Are both objects equal: "
                           + opDouble1.equals(opDouble2)); 
    } 
}

输出：

OptionalDouble 1: OptionalDouble[452.13246]
OptionalDouble 2: OptionalDouble[452.13246]
Are both objects equal: true

示例2:

// Java program to demonstrate 
// OptionalDouble.equals(Object obj) method 
  
import java.util.OptionalDouble; 
  
public class GFG { 
  
    public static void main(String[] args) 
    { 
        // Create first OptionalDouble object 
        OptionalDouble opDouble1 
            = OptionalDouble.of(3179464.92); 
  
        System.out.println("OptionalDouble 1: "
                           + opDouble1.toString()); 
  
        // Create second OptionalDouble object 
        OptionalDouble opDouble2 
            = OptionalDouble.of(4521.3246); 
  
        System.out.println("OptionalDouble 2: "
                           + opDouble2.toString()); 
  
        // Check if these two objects are equal 
        // using equals(Object obj) 
        System.out.println("Are both objects equal: "
                           + opDouble1.equals(opDouble2)); 
    } 
}

输出：

OptionalDouble 1: OptionalDouble[3179464.92]
OptionalDouble 2: OptionalDouble[4521.3246]
Are both objects equal: false

参考文献： https://docs.oracle.com/javase/10/docs/api/java/util/OptionalDouble.html#equals?(Object obj)

相关用法

注：本文由纯净天空筛选整理自AmanSingh2210大神的英文原创作品 OptionalDouble equals() method in Java with examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。