较难.txt

用JAVA编写的在线考试系统

第1题：
Given the following code: 
public class Test { 
   void printValue(int m){ 
     do { System.out.println("The value is"+m); 
        } 
     while( --m > 10 ) 
   } 
   public static void main(String arg[]) { 
     int i=10; 
     Test t= new Test(); 
     t.printValue(i); 
   } 
} 
Which will be output? 
A. The value is 8 
B. The value is 9 
C. The value is 10 
D. The value is 11 
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第2题： 
Which of the following statements about declaration are true? 
A. Declaration of primitive types such as boolean, byte and so on does not allocate memory space for the variable. 
B. Declaration of primitive types such as boolean, byte and so on allocates memory space for the variable. 
C. Declaration of nonprimitive types such as String, Vector and so on does not allocate memory space for the object. 
D. Declaration of nonprimitive types such as String, Vector ans so on allocates memory space for the object. 
***

第3题：
In the Java API documentation which sections are included in a class document? 
A. The description of the class and its purpose 
B. A list of methods in its super class 
C. A list of member variable 
D. The class hierarchy 
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第4题：
Given the following code: 
     1) public void modify() { 
     2)   int i, j, k; 
     3)   i = 100; 
     4)   while ( i > 0 ) { 
     5)      j = i * 2; 
     6)      System.out.println (" The value of j is " + j ); 
     7)      k = k + 1; 
     8)      i--; 
     9)   } 
     10) } 
Which line might cause an error during compilation? 
A. line 4 
B. line 6 
C. line 7 
D. line 8 
*** 
第5题： 
Which of the following statements about variables and scope are true? 
A. Local variables defined inside a method are destroyed when the method is exited. 
B. Local variables are also called automatic variables. 
C. Variables defined outside a method are created when the object is constructed. 
D. A method parameter variable continues to exist for as long as the object is needed in which the method is defined. 
***
第6题：
A class design requires that a member variable cannot be accessible directly outside the class. Which modifier should be used to obtain the access control? 
A. public 
B. no modifier 
C. protected 
D. private 
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第7题：
Given the following code fragment: 
    1) String str = null; 
    2) if ((str != null) && (str.length() > 10)) { 
    3)   System.out.println("more than 10"); 
    4) }  
    5) else if ((str != null) & (str.length() < 5)) { 
    6)        System.out.println("less than 5"); 
    7)      } 
    8)      else { System.out.println("end"); } 
Which line will cause error? 
A. line 1 
B. line 2 
C. line 5 
D. line 8 
*** 
第8题：
Which statements about Java code security are true? 
  
A. The bytecode verifier loads all classes needed for the execution of a program. 
B. Executing code is performed by the runtime interpreter. 
C. At runtime the bytecodes are loaded, checked and run in an interpreter. 
D. The class loader adds security by separating the namespaces for the classes of the local file system from those imported from network sources. 
*** 
第9题： 
Given the following code: 
    public class Person{ 
       static int arr[] = new int[10]; 
       public static void main(String a[]) { 
          System.out.println(arr[1];) 
       } 
    } 
Which statement is correct? 
A. When compilation some error will occur. 
B. It is correct when compilation but will cause error when running.
C. The output is zero. 
D. The output is null. 
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第10题：
Given the following code: 
    public class Person{ 
       int arr[] = new int[10]; 
       public static void main(String a[]) { 
          System.out.println(arr[1]); 
       } 
    } 
Which statement is correct? 
A. When compilation some error will occur. 
B. It is correct when compilation but will cause error when running. 
C. The output is zero. 
D. The output is null. 
***
第11题：
public class Parent { 
     public int addValue( int a, int b) { 
         int s; 
         s = a+b; 
         return s; 
     } 
   } 
   class Child extends Parent { 
    
   } 
Which methods can be added into class Child? 
A. int addValue( int a, int b ){// do something...} 
B. public void addValue (){// do something...} 
C. public int addValue( int a ){// do something...} 
D. public int addValue( int a, int b )throws MyException {//do something...} 
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第12题： 
A member variable defined in a class can be accessed only by the classes in the same package. Which 
A. private 
B. no modifier 
C. public 
D. protected 
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第13题：
A public member vairable called MAX_LENGTH which is int type, the value of the variable remains constant value 100. Use a short statement to define the variable. 
A. public int MAX_LENGTH=100; 
B. final int MAX_LENGTH=100; 
C. final public int MAX_LENGTH=100; 
D. public final int MAX_LENGTH=100. 
***
第14题：
Which expressions are correct to declare an array of 10 String objects? 
A. char str[]; 
B. char str[][]; 
C. String str[]; 
D. String str[10]; 
***
第15题：
Which fragments are correct in Java source file? 
A. package testpackage; 
public class Test{//do something...} 
B. import java.io.*; 
package testpackage; 
public class Test{// do something...} 
C. import java.io.*; 
class Person{// do something...} 
public class Test{// do something...} 
D. import java.io.*; 
import java.awt.*; 
public class Test{// do something...} 
***