Java中的 DoubleAccumulator getThenReset() 方法及示例

Java.DoubleAccumulator.getThenReset()是Java中的一个内置方法，其效果等同于 get() 后跟 reset()。首先，它获取当前值，然后重置该值。复位值为零。返回类型是 int。

句法：

public double getThenReset()

参数：该方法不接受任何参数。

返回值：该方法返回重置前的值。

下面的程序说明了上述方法：

方案一：

// Java program to demonstrate
// the getThenReset() method
  
import java.lang.*;
import java.util.concurrent.atomic.DoubleAccumulator;
  
public class GFG {
    public static void main(String args[])
    {
  
        DoubleAccumulator num
            = new DoubleAccumulator(
                Double::sum, 0L);
  
        // accumulate operation on num
        num.accumulate(42);
        num.accumulate(10);
  
        num.get();
        // before getThenReset the value is
        System.out.println("Old value is: "
                           + num);
  
        // getThenResets current value
        num.getThenReset();
  
        // Print after getThenReset operation
        System.out.println("Current value is: "
                           + num);
    }
}

输出：

Old value is: 52.0
Current value is: 0.0

方案二：

// Java program to demonstrate
// the getThenReset() method import java.lang.*;
  
import java.util.concurrent.atomic.DoubleAccumulator;
  
public class GFG {
    public static void main(String args[])
    {
  
        DoubleAccumulator num
            = new DoubleAccumulator(
                Double::sum, 0L);
  
        // accumulate operation on num
        num.accumulate(74);
        num.accumulate(1);
  
        num.get();
        // before getThenReset the value is
        System.out.println("Old value is: "
                           + num);
  
        // getThenResets current value
        num.getThenReset();
  
        // Print after getThenReset operation
        System.out.println("Current value is: "
                           + num);
    }
}

输出：

Old value is: 75.0
Current value is: 0.0