在Java中,下列代码将输出()。 1. public class integerequals 2. { 3. public static void main (String args[]) 4. { 5. Integer a= new Integer(3); 6. Integer b= new Integer(3); 7. System.out.println(a==b); 8. } 9. }
第1题:
class Super { public Integer getLenght() { return new Integer(4); } } public class Sub extends Super { public Long GetLenght() { return new Long(5); } public static void main(String[] args) { Super sooper = new Super(); Sub sub = new Sub(); System.out.println( sooper.getLenght().toString() + “,” + sub.getLenght().toString() ); } } What is the output?()
第2题:
1. public class Outer{ 2. public void someOuterMethod() { 3. // Line 3 4. } 5. public class Inner{} 6. public static void main( String[]argv ) { 7. Outer o = new Outer(); 8. // Line 8 9. } 10. } Which instantiates an instance of Inner?()
第3题:
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?()
第4题:
现有: 1. class HorseRadish { 2. // insert code here 3. protected HorseRadish(int x) { 4. System.out.println("bok choy"); 5. } 6. } 7. class Wasabi extends HorseRadish { 8. public static void main(String [] args) { 9. Wasabi w = new Wasabi(); 10. } 11. } 分别插入到第 2 行,哪两项允许代码编译并产生"bok choy" 输出结果?()
第5题:
1. class Calc { 2. public static void main(String [] args) { 3. try { 4. int x = Integer.parseInt("42a"); 5. //insert code here 6. System.out.print("oops "); 7. } 8. } 9. } 下面哪两行分别插入到第五行,会导致输出“oops”?()
第6题:
public static void main(String[]args){ Integer i=new Integer(1)+new Integer(2); switch(i){ case3:System.out.println("three");break; default:System.out.println("other");break; } } Whatistheresult?()
第7题:
1. public class enclosingone ( 2. public class insideone{} 3. ) 4. public class inertest( 5. public static void main (string[]args)( 6. enclosingone eo= new enclosingone (); 7. //insert code here 8. ) 9. ) Which statement at line 7 constructs an instance of the inner class?()
第8题:
1. import java.util.*; 2. 3. Class FindStuff { 4. public static void main(String [] args) { 5. // insert code here 6. c.put("x", 123); 7. } 8. } 分别插入到第5行,哪三行允许代码编译?()
第9题:
three
other
Anexceptionisthrownatruntime.
Compilationfailsbecauseofanerroronline12.
Compilationfailsbecauseofanerroronline13.
Compilationfailsbecauseofanerroronline15.
第10题:
编译器将显示第7行有错误
程序编译并打印true
程序编译并打印false
程序编译但在第7行引起了一个运行期意外
第11题:
Map c = new SortedMap();
HashMap c = new HashMap();
HashMap c = new Hashtable();
SortedMap c = new TreeMap();
第12题:
Class A
Compilation fails.
An exception is thrown at line 2.
An exception is thrown at line 6.
The code executes with no output.
第13题:
public class Test { public static void add3 (Integer i) { int val = i.intValue(); val += 3; i = new Integer(val); } public static void main(String args[]) { Integer i = new Integer(0); add3(i); System.out.println(i.intValue()); } } What is the result? ()
第14题:
class Beta { public static void main(String [] args) { Integer x = new Integer(6) * 7; if (x != 42) { System.out.print("42 "); } else if (x 〈 new Integer(44-1)) { System.out.println("less"); } else { System.out.print("done"); } } } 结果是什么?()
第15题:
1. public class A { 2. void A() { 3. System.out.println(“Class A”); 4. } 5. public static void main(String[] args) { 6. new A(); 7. } 8. } What is the result?()
第16题:
public static void main( String[] args ) { Integer a = new Integer(10); Integer b = new Integer(10); Integer c = a; int d = 10; double e = 10.0; } Which three evaluate to true?()
第17题:
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?()
第18题:
1. import java.util.*; 2. public class Example { 3. public static void main(String[] args) { 4. // insert code here 5. set.add(new integer(2)); 6. set.add(new integer(l)); 7. System.out.println(set); 8. } 9. } Which code, inserted at line 4, guarantees that this program will output [1,2]? ()
第19题:
public class test { public static void add3 (Integer i){ int val = i.intValue ( ); val += 3; i = new Integer (val); } public static void main (String args [ ] ) { Integer i = new Integer (0); add3 (i); system.out.printIn (i.intValue ( ) ); } } What is the result?()
第20题:
(a == c)
(d == e)
(b == d)
(a == b)
(b == c)
(d == 10.0)
第21题:
Set set = new TreeSet();
Set set = new HashSet();
Set set = new SortedSet();
List set = new SortedList();
Set set = new LinkedHashSet();
第22题:
Compilation will fail.
The program prints “0”.
The program prints “3”.
Compilation will succeed but an exception will be thrown at line 3.
第23题:
less
42
done
编译失败