Java中的 AtomicLong decrementAndGet() 方法及示例

Java.util.concurrent.atomic.AtomicLong.decrementAndGet()是Java中的一种内置方法，它将前一个值减一并返回更新后的值，该值是数据类型long 。

句法：

public final long decrementAndGet()

参数：该函数不接受单个参数。
返回值：函数将减量运算后的值返回到前一个值。

下面的程序说明了上述方法：

方案一：

Java

// Java program that demonstrates
// the decrementAndGet() function
 
import java.util.concurrent.atomic.AtomicLong;
 
public class GFG {
    public static void main(String args[])
    {
 
        // Initially value as 0
        AtomicLong val = new AtomicLong(0);
 
        System.out.println("Previous value: "
                           + val);
 
        // Decrement and get
        long res
            = val.decrementAndGet();
 
        // Prints the updated value
        System.out.println("Current value: "
                           + res);
    }
}

输出：

Previous value: 0
Current value: -1

方案二：

Java

// Java program that demonstrates
// the decrementAndGet() function
 
import java.util.concurrent.atomic.AtomicLong;
 
public class GFG {
    public static void main(String args[])
    {
 
        // Initially value as 18
        AtomicLong val = new AtomicLong(18);
 
        System.out.println("Previous value: "
                           + val);
 
        // Decrement and get new value
        long res = val.decrementAndGet();
 
        // Prints the updated value
        System.out.println("Current value: "
                           + res);
    }
}

输出：

Previous value: 18
Current value: 17

参考： https: Java/util/concurrent/atomic/AtomicLong.html#decrementAndGet-