java.util.concurrent.atomic.AtomicInteger.compareAndSet()是Java中的一種內置方法,如果當前值等於參數給定的期望值,則將值設置為參數中的傳遞值。該函數返回一個布爾值,該布爾值使我們了解更新是否完成。
用法:
public final boolean compareAndSet(int expect, int val)
參數:該函數接受兩個強製性參數,如下所述:
- expect:它指定原子對象應為的值。
- val:如果原子整數等於期望值,則該值指定要更新的值。
返回值:該函數返回一個布爾值,成功則返回true,否則返回false。
以下程序演示了該函數:
示例1:
// Java Program to demonstrates
// the compareAndSet() function
import java.util.concurrent.atomic.AtomicInteger;
public class GFG {
public static void main(String args[])
{
// Initially value as 0
AtomicInteger val = new AtomicInteger(0);
// Prints the updated value
System.out.println("Previous value: "
+ val);
// Checks if previous value was 0
// and then updates it
boolean res = val.compareAndSet(0, 6);
// Checks if the value was updated.
if (res)
System.out.println("The value was"
+ " updated and it is "
+ val);
else
System.out.println("The value was "
+ "not updated");
}
}
輸出:
Previous value: 0 The value was updated and it is 6
示例2:
// Java Program to demonstrates
// the compareAndSet() function
import java.util.concurrent.atomic.AtomicInteger;
public class GFG {
public static void main(String args[])
{
// Initially value as 0
AtomicInteger val
= new AtomicInteger(0);
// Prints the updated value
System.out.println("Previous value: "
+ val);
// Checks if previous value was 0
// and then updates it
boolean res = val.compareAndSet(10, 6);
// Checks if the value was updated.
if (res)
System.out.println("The value was"
+ " updated and it is "
+ val);
else
System.out.println("The value was "
+ "not updated");
}
}
輸出:
Previous value: 0 The value was not updated
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注:本文由純淨天空篩選整理自gopaldave大神的英文原創作品 AtomicInteger compareAndSet() method in Java with examples。非經特殊聲明,原始代碼版權歸原作者所有,本譯文未經允許或授權,請勿轉載或複製。