如雲似水

喵喵~又來嘍！之前在看SCJP的時候又遇到了些不會的題目，不過@@"那時沒電腦，所以沒辦法把問題貼出來問大家^^"
回家後我看了看大約有25題吧！我決定把他分成兩次問^_^
順便提一下讓我很開心的事情就是這份考題我全都看過一遍嘍！等把不會的題目都搞懂再複習一次後我就要去考考看啦！希望可以考到XD

Auto boxing

40.
Given:
25. A a = new A();
26. System.out.println(a.doit(4, 5));
What is the result?
 
A. Line 26 prints "a" to System.out.
B. Line 26 prints "b" to System.out.
C. An exception is thrown at line 26 at runtime.
D. Compilation of class A will fail due to an error in line 6.


67.
Given:
11. public void testIfA() {
12.     if (testIfB("True")) {
13.         System.out.println("True");
14.     } else {
15.         System.out.println("Not true");
16.     }
17. }
18. public Boolean testIfB(String str) {
19.     return Boolean.valueOf(str);
20. }
What is the result when method testIfA is invoked?
A. True
B. Not true
C. An exception is thrown at runtime.
D. Compilation fails because of an error at line 12.
E. Compilation fails because of an error at line 19.


101.
Given:
1.  public class Boxer1{
2.      Integer i;
3.      int x;
4.      public Boxer1(int y) {
5.          x = i+y;
6.          System.out.println(x);
7.      }
8.      public static void main(String[] args) {
9.          new Boxer1(new Integer(4));
10.    }
11. }

What is the result?
A. The value "4" is printed at the command line.
B. Compilation fails because of an error in line 5.
C. Compilation fails because of an error in line 9.
D. A NullPointerException occurs at runtime.
E. A NumberFormatException occurs at runtime.
F. An IllegalStateException occurs at runtime.


114.
Given:
1. public class Target {
2.     private int i = 0;
3.     public int addOne(){
4.         return ++i;
5.     }
6. }

And:
1. public class Client {
2.     public static void main(String[] args){
3.         System.out.println(new Target().addOne());
4.     }
5. }

Which change can you make to Target without affecting Client?
A. Line 4 of class Target can be changed to return i++;
B. Line 2 of class Target can be changed to private int i = 1;
C. Line 3 of class Target can be changed to private int addOne(){
D. Line 2 of class Target can be changed to private Integer i = 0;


125.
 


166.
Given:

10. public class Bar {
11.     static void foo( int... x ) {
12.         // insert code here
13.     }
14. }

Which two code fragments, inserted independently at line 12, will allow the class to compile? (Choose two.)
A. foreach( x ) System.out.println(z);
B. for( int z : x ) System.out.println(z);
C. while( x.hasNext() ) System.out.println( x.next() );
D. for( int i=0; i< x.length; i++ ) System.out.println(x[i]);


259.
Given:

35. String #name = "Jane Doe";
36. int $age = 24;
37. Double _height = 123.5;
38. double ~temp = 37.5;
Which two statements are true? (Choose two.)
A. Line 35 will not compile.
B. Line 36 will not compile.
C. Line 37 will not compile.
D. Line 38 will not compile.


For-each loop

96.
Given:

11. public static void main(String[] args) {
12.     for (int i = 0; i <= 10; i++) {
13.         if (i > 6) break;
14.     }
15.     System.out.println(i);
16. }

What is the result?
A. 6
B. 7
C. 10
D. 11
E. Compilation fails.
F. An exception is thrown at runtime.


Modifier

3.
 


51.
Given classes defined in two different files:
1. package util;
2. public class BitUtils {
3.     private static void process(byte[] b) {}
4. }
1. package app;
2. public class SomeApp {
3.     public static void main(String[] args) {
4.         byte[] bytes = new byte[256];
5.         // insert code here
6.     }
7. }
What is required at line 5 in class SomeApp to use the process method of BitUtils?
A. process(bytes);
B. BitUtils.process(bytes);
C. app.BitUtils.process(bytes);
D. util.BitUtils.process(bytes);
E. import util.BitUtils.*; process(bytes);
F. SomeApp cannot use the process method in BitUtils.


221.