ÎÒµÄJAVAϰÌ⼯2 ÏÂÔØ±¾ÎÄ

ÄÚÈÝ·¢²¼¸üÐÂʱ¼ä : 2025/9/4 5:10:31ÐÇÆÚÒ» ÏÂÃæÊÇÎÄÕµÄÈ«²¿ÄÚÈÝÇëÈÏÕæÔĶÁ¡£

23£®ÒÔϳÌÐòƬ¶Î£¬ÏÂÁÐÄĸöÑ¡Ïî²åÈëµ½µÚ2Ðн«ÒýÆð±àÒë´íÎó?( ) 1. package mypackage; 2.

3. class MyClass{

4. //do something 5. }

A. public class MainClass{ } B. package mypackage1; C. class B{ } D. import java. util.*;

24£®ÒÔϳÌÐò´úÂ룬ÎÞ·¨Í¨¹ý±àÒëµÄÊÇ( )¡£ A. class A{

int i=O;

public void method(){

System.out.println (i); } }

B. class A{

int i=0; }

class B{

public void method(){

System.out.println (A.i); } }

C. class A{

public int i=0;

public static void method(){

System. out.println (newA() .i); } }

D. class A{

public static int i=0;

public static void method(){ System.out.println (i); ) }

25£®ÏÂÁдúÂëÔÚ±àÒëʱ»á·¢Éú´íÎó£¬ÏÂÃæÄÄÖÖÐ޸ĿÉÒÔ¸üÕý´íÎó?( ) class Test {

private int m;

public static void fun(){ System.out.println(m); }

5

}

A£®½«private int m¸ÄΪprotected int m B£®½«private int m¸ÄΪpublic int m C£®½«phvate int m¸ÄΪstatic int m D£®½«private int m¸ÄΪint m

Èý¡¢³ÌÐòÔĶÁÌâ

1£®ÔĶÁÏÂÃæµÄ³ÌÐò£¬³ÌÐò±£´æÎªTest£®java£º

1. public class Test{ 2. short mValue;

3. public static void main(String[] args){ 4. int a=32; 5. int b=56;

6. Test os=new Test (a+b); 7. os.Show (); 8. }

9. protected Test (short aValue) { 10. mValue= aValue; 11. }

12. public void Show() {

13. System. out .println (mValue); 14. } 15. }

ÉÏÃæµÄ³ÌÐò±àÒëÊÇ·ñ³É¹¦?Èç¹û±àÒë³ö´í£¬Ö¸³öÄÄÐгö´í£¬²¢ËµÃ÷ÀíÓÉ£»Èç¹û±àÒëÕýÈ·£¬ÔËÐнá¹ûÊÇʲô?

2£®ÔĶÁÏÂÃæµÄ³ÌÐò£º

1 public class Test{

2 public static void main (String argv [ ] ) { 3 Bird b=new Bird(); 4 b. fly (3); 5 } 6 }

7 class Bird{

8. static int Type=2;

9. private void fly(int an_Type) { 10. Type= an_Type;

11. System. out .println (\12. } 13. }

6

ÉÏÃæµÄ³ÌÐò±àÒëÊÇ·ñ³É¹¦?Èç¹û±àÒë³ö´í£¬Ö¸³öÄÄÐгö´í£¬²¢ËµÃ÷ÀíÓÉ£»Èç¹û±àÒëÕýÈ·£¬ ÔËÐнá¹ûÊÇʲô?

3£®×ÐϸÔĶÁÏÂÃæµÄ³ÌÐò´úÂ룬Èô¾­±àÒëºÍÔËÐкó£¬Çëд³ö´òÓ¡½á¹û¡£ class StaticTest { static int x=l; int y;

StaticTest () { y++; }

public static void main (String args [] ) { StaticTest st=new StaticTest (); System.out.println (\

System. out.println (\ st=new StaticTest ();

System.out.println (\ System. out.println (\}

static { x++; }

4£®Ð´³öÏÂÁгÌÐò´úÂëµÄÔËÐнá¹û¡£

public class PassTest{ float ptValue;

public void changeInt(int value){ value=il; }

public void changeStr(String value){ value=new String(\ }

public void changeObjValue( PassTest ref){ ref.ptValue=22; }

public static void main(String args[ ] ){ String str; int val;

PassTest pt=new PassTest(); val=33;

pt.changeInt (val);

System.out.println(\ str=new String (\ pt.changeStr (str);

System. out.println(\ pt.ptValue=44;

7

pt.changeObjValue(pt);

System.out.println(\£»

} }

5£®Ð´³öÏÂÁгÌÐò´úÂëµÄÔËÐнá¹û£º

class Test {

public static String ss=\º¼Öݵç×ӿƼ¼´ó\ public String ms= \¼ÆËã»úѧԺ\ public void printInfo () {

System. out.println (\ }

public static void main (String [] args) { Test obj1, obj2; obj1=new Test(); obj2=new Test();

obj1.ss=\Õã½­¹¤Òµ´óѧ\obj1.ms= \Èí¼þѧԺ\obj1.printInfo(); obj2.printInfo(); } }

6£®ÔĶÁÒÔϳÌÐò£¬»Ø´ðÎÊÌâ¡£ package packagel; class ClassA{

public void printInfo(){

System.out.println (\ } }

package package2;

import packagel.ClassA; public class ClassB{

public static voidmain(String [] args){ new ClassA().printInfo(); } }

(1)ÉÏÃæÁ½¸öÀàÊÇÔÚͬһ¸öÔ´³ÌÐòÎļþÖÐÂð?

(2)ÒÔÉϳÌÐò±àÒëÊÇ·ñÕý³£?Èô±àÒëÕý³£ÔòÔËÐнá¹ûÊÇʲô?

8