单选题现有:  class Tree {  private static String tree = "tree ";  String getTree ()  {  return tree;  }       }  class Elm extends Tree {  private static String tree = "elm ";  public static void main (String  []  args)  {       new Elm() .go (new Tree())  ;  

题目
单选题
现有:  class Tree {  private static String tree = "tree ";  String getTree ()  {  return tree;  }       }  class Elm extends Tree {  private static String tree = "elm ";  public static void main (String  []  args)  {       new Elm() .go (new Tree())  ;      } }  void go (Tree t)  {  String  s =  t.getTree () +Elm.tree  +  tree  +   (new  Elm() .getTree ()) ;      System.out.println (s) ;}     结果为:()
A

 elm elm elm elm

B

 tree elm elm elm

C

 tree elm elm tree

D

 tree elm tree elm


相似考题
更多“单选题现有:  class Tree {  private static String tree = "tree ";  String getTree ()  {  return tree;  }       }  class Elm extends Tree {  private static String tree = "elm ";  public static void main (String  []  args)  {       new Elm() .go (new Tree())  ;  ”相关问题
  • 第1题:

    下面程序段的输出结果为 public class Test { public static void main(String args[]) { boolean a,b,c; a=(3<5); b=(a==true); System.out.println(”a=”+a+”b=+b) ; c=(b==false); System.out.printhln(”b=”+b+”c=”+c) ; } }

    A.a=true b=false b=true c=false

    B.a=true b=false b=true c=true

    C.a=true b=true b=tree c=false

    D.a=false b=false b=tree c=false


    正确答案:C
    解析:本题考查关系运算符<和=。题目中a=(3<5);比较3和5的大小,因为3<5,返回true给a:b=(a==true);判断a是否为真,因为a确实为真,返回true给b;c =(b==false);判断b是否为假,因为b不为假,返回false给c。最后结果a=true,b=tree, b==true,c=false,选项C正确。

  • 第2题:

    现有:  class Tree {  private static String tree = "tree ";  String getTree ()  {  return tree;  }       }  class Elm extends Tree {  private static String tree = "elm ";  public static void main (String  []  args)  {       new Elm() .go (new Tree())  ;      } }  void go (Tree t)  {  String  s =  t.getTree () +Elm.tree  +  tree  +   (new  Elm() .getTree ()) ;      System.out.println (s) ;}     结果为:()                 

    • A、 elm elm elm elm
    • B、 tree elm elm elm
    • C、 tree elm elm tree
    • D、 tree elm tree elm

    正确答案:C

  • 第3题:

    class Mineral {   static String shiny() { return "1"; }   }   class Granite extends Mineral {   public static void main(String [] args) {   String s = shiny() + getShiny();   s = s + super.shiny();   System.out.println(s);   }   static String getShiny() { return shiny(); }   }   结果为:()  

    • A、3
    • B、12
    • C、111
    • D、编译失败

    正确答案:D

  • 第4题:

    下面哪些选项是正确的main方法说明?()

    • A、 public main(String args[])
    • B、 public static void main(String args[])
    • C、 private static void main(String args[])
    • D、 void main()

    正确答案:B

  • 第5题:

    现有:  class Guy {String greet()    {return "hi";  }  }  class Cowboy extends Guy  (  String greet()    (  return "howdy  ¨;    )  )  class Surfer extends Guy  (String greet()    (return "dude! ";)) class Greetings  {  public static void main (String  []  args)    {  Guy  []  guys =  ( new Guy(), new Cowboy(), new Surfer()  );  for (Guy g:  guys) System.out.print (g.greet()};  }  }  结果为:() 

    • A、 hi howdy dude!
    • B、运行时异常被抛出。
    • C、第7行出现一个错误,编译失败。
    • D、第8行出现一个错误,编译失败。

    正确答案:A

  • 第6题:

    Public class test (  Public static void stringReplace (String text)  (  Text = text.replace (‘j’ , ‘i’);  )  public static void bufferReplace (StringBuffer text)  (  text = text.append (“C”)  )   public static void main (String args[]}  (  String textString = new String (“java”); StringBuffer text BufferString = new StringBuffer (“java”);  stringReplace (textString);  bufferReplace (textBuffer);  System.out.printLn (textString + textBuffer);  ) )  What is the output?()


    正确答案:javajavaC

  • 第7题:

    Given the following code:     1) class Parent {     2) private String name;     3) public Parent(){}     4) }  5) public class Child extends Parent {     6) private String department;  7) public Child() {}  8) public String getValue(){ return name; }     9) public static void main(String arg[]) {     10) Parent p = new Parent();     11) }  12) }  Which line will cause error?()   

    • A、 line 3
    • B、 line 6
    • C、 line 7
    • D、 line 8
    • E、 line 10

    正确答案:D

  • 第8题:

    单选题
    final class Tree {  private static String tree = "tree ";  String getTree() { return tree; }  }  class Elm extends Tree {  private static String tree = "elm "; public static void main(String [] args) {  new Elm().go(new Tree());  }  void go(Tree t) {  String s = t.getTree()+Elm.tree+tree+(new Elm().getTree());  System.out.println(s);  } }  结果为:()
    A

    elm elm elm elm

    B

    tree elm elm elm

    C

    tree elm tree elm

    D

    编译失败


    正确答案: C
    解析: 暂无解析

  • 第9题:

    单选题
    public class Item {  private String desc;  public String getDescription() { return desc; }  public void setDescription(String d) { desc = d; } public static void modifyDesc(Item item, String desc) {  item = new Item();  item.setDescription(desc);  }  public static void main(String[] args) {  Item it = new Item();  it.setDescription(”Gobstopper”);  Item it2 = new Item();  it2.setDescription(”Fizzylifting”);  modifyDesc(it, “Scrumdiddlyumptious”);  System.out.println(it.getDescription());  System.out.println(it2.getDescription());  }  }  What is the outcome of the code? ()
    A

     Compilation fails.

    B

     Gobstopper      Fizzylifting

    C

     Gobstopper     Scrumdiddlyumptious

    D

     Scrumdiddlyumptious     Fizzylifltng

    E

     Scrumdiddlyumptious     Scrumdiddlyumptious


    正确答案: A
    解析: 暂无解析

  • 第10题:

    单选题
    public class Plant {  private String name;  public Plant(String name) { this.name = name; }  public String getName() { return name; }  }  public class Tree extends Plant {  public void growFruit() { }  public void dropLeaves() { }  }  Which is true?()
    A

     The code will compile without changes.

    B

     The code will compile if public Tree() { Plant(); } is added to the Tree class.

    C

     The code will compile if public Plant() { Tree(); } is added to the Plant class.

    D

     The code will compile if public Plant() { this(”fern”); } is added to the Plant class.

    E

     The code will compile if public Plant() { Plant(”fern”); } is added to the Plant class.


    正确答案: C
    解析: 暂无解析

  • 第11题:

    单选题
    import java.io.*;  public class Forest implements Serializable {  private Tree tree = new Tree();  public static void main(String [] args) {  Forest f= new Forest();  try {  FileOutputStream fs = new FileOutputStream(”Forest.ser”);  ObjectOutputStream os = new ObjectOutputStream(fs);  os.writeObject(f); os.close();  } catch (Exception ex) { ex.printStackTrace(); }  }  }  class Tree { }  What is the result?()
    A

     Compilation fails.

    B

     An exception is thrown at runtime.

    C

     An instance of Forest is serialized.

    D

     A instance of Forest and an instance of Tree are both serialized.


    正确答案: B
    解析: 暂无解析

  • 第12题:

    单选题
    class Mineral {   static String shiny() { return "1"; }   }   class Granite extends Mineral {   public static void main(String [] args) {   String s = shiny() + getShiny();   s = s + super.shiny();   System.out.println(s);   }   static String getShiny() { return shiny(); }   }   结果为:()
    A

    3

    B

    12

    C

    111

    D

    编译失败


    正确答案: D
    解析: 暂无解析

  • 第13题:

    考虑如下代码:

    class Tree{}

    class Pine extends Tree{}

    class Oak extends Tree{}

    public class Forest {

    public static void main( String[] args ) {

    Tree tree = new Pine();

    if( tree instanceof Pine )

    System.out.println( "Pine" );

    if( tree instanceof Tree )

    System.out.println( "Tree" );

    if( tree instanceof Oak )

    System.out.println( "Oak" );

    else

    System.out.println( "Oops" );

    }

    }

    则输出结果中有哪些?

    A.Pine B.Tree C.Forest D.Oops E.无输出


    正确答案:ABD

  • 第14题:

    Which declarations will allow a class to be started as a standalone program?()  

    • A、public void main(String args[])
    • B、public void static main(String args[])
    • C、public static main(String[] argv)
    • D、final public static void main(String [] array)
    • E、public static void main(String args[])

    正确答案:D,E

  • 第15题:

    public class Item {  private String desc;  public String getDescription() { return desc; }  public void setDescription(String d) { desc = d; } public static void modifyDesc(Item item, String desc) {  item = new Item();  item.setDescription(desc);  }  public static void main(String[] args) {  Item it = new Item();  it.setDescription(”Gobstopper”);  Item it2 = new Item();  it2.setDescription(”Fizzylifting”);  modifyDesc(it, “Scrumdiddlyumptious”);  System.out.println(it.getDescription());  System.out.println(it2.getDescription());  }  }  What is the outcome of the code? ()

    • A、 Compilation fails.
    • B、 Gobstopper      Fizzylifting
    • C、 Gobstopper     Scrumdiddlyumptious
    • D、 Scrumdiddlyumptious     Fizzylifltng
    • E、 Scrumdiddlyumptious     Scrumdiddlyumptious

    正确答案:B

  • 第16题:

    声明Java独立应用程序main()方法时,正确表达是()。

    • A、public static void main(String[]args){…}
    • B、private static void main(String args[]){…}
    • C、public void main(String args[]){…}
    • D、public static void main(){…}

    正确答案:A

  • 第17题:

    final class Tree {  private static String tree = "tree ";  String getTree() { return tree; }  }  class Elm extends Tree {  private static String tree = "elm "; public static void main(String [] args) {  new Elm().go(new Tree());  }  void go(Tree t) {  String s = t.getTree()+Elm.tree+tree+(new Elm().getTree());  System.out.println(s);  } }  结果为:() 

    • A、elm elm elm elm
    • B、tree elm elm elm
    • C、tree elm tree elm
    • D、编译失败

    正确答案:D

  • 第18题:

    public class Plant {  private String name;  public Plant(String name) { this.name = name; }  public String getName() { return name; }  }  public class Tree extends Plant {  public void growFruit() { }  public void dropLeaves() { }  }  Which is true?() 

    • A、 The code will compile without changes.
    • B、 The code will compile if public Tree() { Plant(); } is added to the Tree class.
    • C、 The code will compile if public Plant() { Tree(); } is added to the Plant class.
    • D、 The code will compile if public Plant() { this(”fern”); } is added to the Plant class.
    • E、 The code will compile if public Plant() { Plant(”fern”); } is added to the Plant class.

    正确答案:D

  • 第19题:

    import java.io.*;  public class Forest implements Serializable {  private Tree tree = new Tree();  public static void main(String [] args) {  Forest f= new Forest();  try {  FileOutputStream fs = new FileOutputStream(”Forest.ser”);  ObjectOutputStream os = new ObjectOutputStream(fs);  os.writeObject(f); os.close();  } catch (Exception ex) { ex.printStackTrace(); }  }  }  class Tree { }  What is the result?() 

    • A、 Compilation fails.
    • B、 An exception is thrown at runtime.
    • C、 An instance of Forest is serialized.
    • D、 A instance of Forest and an instance of Tree are both serialized.

    正确答案:B

  • 第20题:

    填空题
    Public class test (  Public static void stringReplace (String text)  (  Text = text.replace (‘j’ , ‘i’);  )  public static void bufferReplace (StringBuffer text)  (  text = text.append (“C”)  )   public static void main (String args[]}  (  String textString = new String (“java”);  StringBuffer text BufferString = new StringBuffer (“java”);  stringReplace (textString);  BufferReplace (textBuffer);  System.out.printLn (textString + textBuffer);  )  )   What is the output?()

    正确答案: JAVAJAVA
    解析: 暂无解析

  • 第21题:

    多选题
    Which declarations will allow a class to be started as a standalone program?()
    A

    public void main(String args[])

    B

    public void static main(String args[])

    C

    public static main(String[] argv)

    D

    final public static void main(String [] array)

    E

    public static void main(String args[])


    正确答案: C,E
    解析: 暂无解析

  • 第22题:

    单选题
    Given the following code:     1) class Parent {     2) private String name;     3) public Parent(){}     4) }  5) public class Child extends Parent {     6) private String department;  7) public Child() {}  8) public String getValue(){ return name; }     9) public static void main(String arg[]) {     10) Parent p = new Parent();     11) }  12) }  Which line will cause error?()
    A

     line 3

    B

     line 6

    C

     line 7

    D

     line 8

    E

     line 10


    正确答案: D
    解析: 第8行的getValue()试图访问父类的私有变量,错误。

  • 第23题:

    单选题
    现有:  class Tree {  private static String tree = "tree ";  String getTree ()  {  return tree;  }       }  class Elm extends Tree {  private static String tree = "elm ";  public static void main (String  []  args)  {       new Elm() .go (new Tree())  ;      } }  void go (Tree t)  {  String  s =  t.getTree () +Elm.tree  +  tree  +   (new  Elm() .getTree ()) ;      System.out.println (s) ;}     结果为:()
    A

     elm elm elm elm

    B

     tree elm elm elm

    C

     tree elm elm tree

    D

     tree elm tree elm


    正确答案: C
    解析: 暂无解析

  • 第24题:

    单选题
    下面哪些选项是正确的main方法说明?()
    A

     public main(String args[])

    B

     public static void main(String args[])

    C

     private static void main(String args[])

    D

     void main()


    正确答案: B
    解析: 暂无解析