Java中的 LongAdder sumThenReset() 方法及示例

Java中的LongAdder 类创建一个初始和为零的新加法器。 Java.LongAdder.sumThenReset()是Java中的内置方法，相当于 sum() then reset() 函数。首先计算总和，然后将其重置为值 0。创建类的对象时，其初始值为零。

句法：

public long sumThenReset()

参数：该函数不接受任何参数。

返回值：该方法返回一个 long 值，该值是此 LongAdder 在重置为 0 之前的当前总和。

下面的程序演示了上述函数：

方案一：

// Java program to demonstrate
// the LongAdder.sumThenReset() method
  
import java.lang.*;
import java.util.concurrent.atomic.LongAdder;
  
public class GFG {
    public static void main(String args[])
    {
  
        // Initialized with 0
        LongAdder num = new LongAdder();
  
        // Print the initial value
        System.out.println("Initial value is: "
                           + num);
  
        // Add 6 to it
        num.add(6);
  
        // Print the final value
        System.out.println("After addition"
                           + " of 6, value is: "
                           + num);
  
        // Add 5 to it
        num.add(5);
  
        // Print the final value
        System.out.println("After addition"
                           + " of 5, value is: "
                           + num);
  
        // sumThenReset operation on num
        System.out.println("Returned sum before reset: "
                           + num.sumThenReset());
  
        // Print the current value
        System.out.println("Current value is: "
                           + num);
    }
}

输出：

Initial value is: 0
After addition of 6, value is: 6
After addition of 5, value is: 11
Returned sum before reset: 11
Current value is: 0

方案二：

// Java program to demonstrate
// the LongAdder.sumThenReset() method
  
import java.lang.*;
import java.util.concurrent.atomic.LongAdder;
  
public class GFG {
    public static void main(String args[])
    {
  
        // Initialized with 0
        LongAdder num = new LongAdder();
  
        // Print the initial value
        System.out.println("Initial value is: "
                           + num);
  
        // Add 10 to it
        num.add(10);
  
        // Print the final value
        System.out.println("After addition"
                           + " of 10, value is: "
                           + num);
  
        // Add 100 to it
        num.add(100);
  
        // Print the final value
        System.out.println("After addition"
                           + " of 100, value is: "
                           + num);
  
        // sumThenReset operation on num
        System.out.println("Returned sum before reset: "
                           + num.sumThenReset());
  
        // Print the current value
        System.out.println("Current value is: "
                           + num);
    }
}

输出：

Initial value is: 0
After addition of 10, value is: 10
After addition of 100, value is: 110
Returned sum before reset: 110
Current value is: 0