单项选择题
public class SyncTest {
private int x；
private int y；
private synchronized void setX（ int i ） { x = i； }
private synchronized void setY（ int i ） { y = i； }
public void setXY（ int i ） { setX（i）； setY（i）； }
public synchronized boolean check（） { return x != y； }
}
Under which condition will check return true when called from a different class？ （）
A. check can never return true.
B. check can return true when setXY is called by multiple threads.
C. check can return true when multiple threads call setX and setY separately.
D. check can return true only if SyncTest is changed to allow x and y to be set separately.
相关考题
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单项选择题
package foo； public class Outer { public static class Inner { } } Which statement is true？（）
A. Compilation fails.
B. An instance of the Inner class can be constructed with “new Outer.Inner（）”.
C. An instance of the Inner class cannot be constructed outside of package foo.
D. An instance of the Inner class can be constructed only from within the Outer class.
E. From within the package foo， and instance of the Inner class can be constructed with “new Inner（）”. -
单项选择题
class A { public A（） { System.out.println（“hello from a”）； } } class B extends A { public B （） { System.out.println（“hello from b”）； super（）； } } public class Test { public static void main（String args[]） { A a = new B（）； } } What is the result when main is executed？（）
A. Compilation fails.
B. hello from a
C. hello from b
D. hello from b hello from a
E. hello from a hello from b -
多项选择题
Whichtwoarebenefitsoffullyencapsulatingaclass？（）
A. Performance of class methods is improved.
B. Implementation details of the class are hidden.
C. Access modifiers can be omitted on class data members.
D. Code that uses the encapsulation class can access data members directly.
E. Internal operation of the class can be modified without impacting clients of that class.
