Java中的 AtomicLongArray decrementAndGet() 方法及示例
Java.util.concurrent.atomic.AtomicLongArray.decrementAndGet()是Java中的一种内置方法,它以原子方式将给定索引处的元素递减一个。该方法将索引值和要添加的值作为参数,并在该索引处返回更新后的值。
句法:
public final long decrementAndGet(int i)
参数:该函数接受一个参数i ,它是执行减一操作的索引。
返回值:该函数返回long中的更新值。
下面的程序说明了上述方法:
方案一:
// Java program that demonstrates
// the compareAndSet() function
import java.util.concurrent.atomic.AtomicLongArray;
public class GFG {
public static void main(String args[])
{
// Initializing an array
long a[] = { 1, 2, 3, 4, 5 };
// Initializing an AtomicLongArray with array a
AtomicLongArray arr = new AtomicLongArray(a);
// Displaying the AtomicLongArray
System.out.println("The array : " + arr);
// Index where operation is performed
int idx = 3;
// Updating the value at
// idx applying decrementAndGet
arr.decrementAndGet(idx);
// Displaying the AtomicLongArray
System.out.println("The array after update : "
+ arr);
}
}
输出:
The array : [1, 2, 3, 4, 5]
The array after update : [1, 2, 3, 3, 5]
方案二:
// Java program that demonstrates
// the compareAndSet() function
import java.util.concurrent.atomic.AtomicLongArray;
public class GFG {
public static void main(String args[])
{
// Initializing an array
long a[] = { 1, 2, 3, 4, 5 };
// Initializing an AtomicLongArray with array a
AtomicLongArray arr = new AtomicLongArray(a);
// Displaying the AtomicLongArray
System.out.println("The array : " + arr);
// Index where operation is performed
int idx = 0;
// Updating the value at
// idx applying decrementAndGet
arr.decrementAndGet(idx);
// Displaying the AtomicLongArray
System.out.println("The array after update : "
+ arr);
}
}
输出:
The array : [1, 2, 3, 4, 5]
The array after update : [0, 2, 3, 4, 5]
参考:
https://docs.oracle.com/javase/8/docs/api/java Java