public class SyncTest ( private int x; private int y; private synchronized void setX (int i) (x=1;) private synchronized void setY (int i) (y=1;) public void setXY(int 1)(set X(i); setY(i);) public synchronized Boolean check() (return x !=y;) ) Under which conditions 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 only return true if SyncTest is changed to allow x and y to be setseparately.
public class SyncTest ( private int x; private int y; private synchronized void setX (int i) (x=1;) private synchronized void setY (int i) (y=1;) public void setXY(int 1)(set X(i); setY(i);) public synchronized Boolean check() (return x !=y;) ) Under which conditions 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 only return true if SyncTest is changed to allow x and y to be setseparately.
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有如下程序:includeusing namespace std;Class TestClass{private:int x,y;public:Te 有如下程序: #include<iostream> using namespace std; Class TestClass { private: int x,y; public: TestClass(int i,int j) { x=i; y=j; } void print() { cout<<“print1”<<endl; } void print()const { cout<<”prinA.printlB.print2C.printl print2D.程序编译时出错。
本题中,鼠标在窗口中单击一下,就在单击的位置生成一个小矩形,如果在小矩形上双击鼠标左键,则删除小矩形。 import java.awt.*; import java.awt.event.*; import javax swing.*; class MousePanel extends JPanel extends MouseMo- tionListener {public MousePanel {addMouseListener(new MouseAdapter {public void mousePressed(MouseEvent evt) {int X=evt.getX; int Y=evt.getY; current=find(x,y); if(current0) add(x,y); } public void mouseClicked(MouseEvent evt) {int X=evt.getX; int Y=evt.getY; if(evt.getClickCount=2) {remove(current); } } }); addMouseMotionListener(this); } public void paintComponent(Graphics g) {super.paintComponent; for(int i=0;insquares;i++) draw(g,i); } public int find(int X,int y) (for(int i=0;insquares;i++) if(squares[i].x-SQUARELENGTH/2= x X=squares[i].x+SQuARELENGTH/2 squares[i].Y-SQUARELENGTH/2 =Y y=squares[i].Y+SQUARELENGTH /2) return i ; return-1 ; } public void draw(Graphics g,int i) {g.drawRect(squares[i].X-SQUARE- LENGTH/2。 squares[i].Y-SQUARELENGTH/2, SQUARELENGTH, SQUARELENGTH); } public void add(int X,int Y) {if(nsquaresMAXNSQUARES) {squares[nsquares]=new Point(x,y); current=nsquares ; nsquares++; repaint; } } public void remove(int n) {if(n0 ‖ n=nsquares)return; Nsquares- -; squares[n]=squares[nsquares]; if(current= =n)current= -l; repaint; } public void mouseMoved(MouseEvent evt) {} public void mouseDragged(MouseEvent evt) {} private static final int SQUARELENGTH=10: private static final int MAXNSQUARES=100; private Point[]squares=new Point[MAX- NSQUARES]; private int nsquares=0; private int current=-l; } class MouseFrame. extends JFramc {public MouseFrame {setTitle("java3"); setSize(300,200); addWindowListener(new WindowAdapter {public void windowClosing(WindowEvent e) {System.exit(0); } }); Container contentPane=getContentPane; contentPane.add(MousePanel); } } public class java3 {public static void main(String[]args) {JFrame. frame=new MouseFrame; frame.show; } }
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下列程序中说明的私有成员是 ______。class Location{int x;public: void init(int initX,int initY);private: int y;public: int SetX();Int SetY();A.xB.yC.SetX(),SetY()D.ABC都是
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.
public class SyncTest ( private int x; private int y; private synchronized void setX (int i) (x=1;) private synchronized void setY (int i) (y=1;) public void setXY(int 1)(set X(i); setY(i);) public synchronized Boolean check() (return x !=y;) ) Under which conditions 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 only return true if SyncTest is changed to allow x and y to be set separately.
10. class Inner { 11. private int x; 12. public void setX( int x) { this.x = x; } 13. public int getX() { return x; } 14. } 15. 16. class Outer { 17. private Inner y; 18. public void setY( Inner y) { this.y = y; } 19. public Inner getY() { return y; } 20. } 21. 22. public class Gamma { 23. public static void main( String[] args) { 24. Outer o = new Outer(); 25. Inner i = new Inner(); 26.int n=10; 27. i.setX(n); 28. o.setY(i); 29. // insert code here 30. System.out.println( o.getY().getX()); 31. } 32. } Which three code fragments, added individually at line 29, produce the output 100?()A、 n = 100;B、 i.setX( 100);C、 o.getY().setX( 100);D、 i = new Inner(); i.setX( 100);E、 o.setY( i); i = new Inner(); i.setX( 100);F、 i = new Inner(); i.setX( 100); o.setY( i);
public class SyncTest { private int x; private int y; public synchronized void setX (int i) (x=1;) public synchronized void setY (int i) (y=1;) public synchronized void setXY(int 1)(set X(i); setY(i);) public synchronized Boolean check() (return x !=y;) } Under which conditions 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 only return true if SyncTest is changed to allow x and y to be set separately.
public abstract class Shape { private int x; private int y; public abstract void draw(); public void setAnchor(int x, int y) { this.x = x; this.y = y; } } Which two classes use the Shape class correctly?()A、 public class Circle implements Shape { private int radius; }B、 public abstract class Circle extends Shape { private int radius; }C、 public class Circle extends Shape { private int radius; public void draw(); }D、 public abstract class Circle implements Shape { private int radius; public void draw(); }E、 public class Circle extends Shape { private int radius;public void draw() {/* code here */} }F、 public abstract class Circle implements Shape { private int radius;public void draw() { / code here */ } }
public class TestFive { private int x; public void foo() { int current = x; x = current + 1; } public void go() { for(int i=0;i5;i++) { new Thread() { public void run() { foo(); System.out.print(x + “, “); } }.start(); }}} Which two changes, taken together, would guarantee the output: 1, 2, 3, 4, 5, ?()A、 Move the line 12 print statement into the foo() method.B、 Change line 7 to public synchronized void go() {.C、 Change the variable declaration on line 3 to private volatile int x;.D、 Wrap the code inside the foo() method with a synchronized( this ) block.E、 Wrap the for loop code inside the go() method with a synchronized block synchronized(this) { // for loop code here }.
多选题10. class Inner { 11. private int x; 12. public void setX( int x) { this.x = x; } 13. public int getX() { return x; } 14. } 15. 16. class Outer { 17. private Inner y; 18. public void setY( Inner y) { this.y = y; } 19. public Inner getY() { return y; } 20. } 21. 22. public class Gamma { 23. public static void main( String[] args) { 24. Outer o = new Outer(); 25. Inner i = new Inner(); 26.int n=10; 27. i.setX(n); 28. o.setY(i); 29. // insert code here 30. System.out.println( o.getY().getX()); 31. } 32. } Which three code fragments, added individually at line 29, produce the output 100?()An = 100;Bi.setX( 100);Co.getY().setX( 100);Di = new Inner(); i.setX( 100);Eo.setY( i); i = new Inner(); i.setX( 100);Fi = new Inner(); i.setX( 100); o.setY( i);
多选题public abstract class Shape { private int x; private int y; public abstract void draw(); public void setAnchor(int x, int y) { this.x = x; this.y = y; } } Which two classes use the Shape class correctly?()Apublic class Circle implements Shape { private int radius; }Bpublic abstract class Circle extends Shape { private int radius; }Cpublic class Circle extends Shape { private int radius; public void draw(); }Dpublic abstract class Circle implements Shape { private int radius; public void draw(); }Epublic class Circle extends Shape { private int radius;public void draw() {/* code here */} }Fpublic abstract class Circle implements Shape { private int radius;public void draw() { / code here */ } }