Test_3(27-8-2014)
Oops,String & Collection
- 1.Select Correct options in given below
- A.
Collection list = new ArrayList();
- B.
ArrayList list = new ArrayList();
- C.
ArrayList list = new ArrayList();
- D.
A,B & C
- 2.3. public class Ouch {4. static int ouch = 7;5. public static void main(String[] args) {6. new Ouch().go(ouch);7. System.out.print(" " + ouch);8. }9. void go(int ouch) {10. ouch++;11. for(int ouch = 3; ouch < 6; ouch++)12. ;13. System.out.print(" " + ouch);14. }15. }
- A.
57
- B.
58
- C.
87
- D.
88
- E.
Compilation fails
- F.
An exception is thrown at runtime
- 3.Class Hexy { public static void main(String[] args) { Integer i = 42; String s = (i<40)?"life":(i>50)?"universe":"everything"; System.out.println(s); }}
- A.
Null
- B.
Life
- C.
Universe
- D.
Everything
- E.
Compilation fails
- F.
. An exception is thrown at runtime
- 4.Given:class Feline { public static void main(String[] args) { Long x = 42L; Long y = 44L; System.out.print(" " + 7 + 2 + " "); System.out.print(foo() + x + 5 + " "); System.out.println(x + y + foo()); } static String foo() { return "foo"; }}
- A.
9 foo47 86foo
- B.
9 foo47 4244foo
- C.
9 foo425 86foo
- D.
9 foo425 4244foo
- E.
72 foo425 86foo
- F.
Compilation fails
- 5.3. interface Vessel { }4. interface Toy { }5. class Boat implements Vessel { }6. class Speedboat extends Boat implements Toy { }7. public class Tree {8. public static void main(String[] args) {9. String s = "0";10. Boat b = new Boat();11. Boat b2 = new Speedboat();12. Speedboat s2 = new Speedboat();13. if((b instanceof Vessel) && (b2 instanceof Toy)) s += "1";14. if((s2 instanceof Vessel) && (s2 instanceof Toy)) s += "2";15. System.out.println(s);16. }17. }
- A.
0
- B.
01
- C.
012
- D.
Compilation fails
- 6.3. public class Theory {4. public static void main(String[] args) {5. String s1 = "abc";6. String s2 = s1;7. s1 += "d";8. System.out.println(s1 + " " + s2 + " " + (s1==s2));9.10. StringBuffer sb1 = new StringBuffer("abc");11. StringBuffer sb2 = sb1;12. sb1.append("d");13. System.out.println(sb1 + " " + sb2 + " " + (sb1==sb2));14. }15. }
- A.
Compilation fails
- B.
The first line of output is abc abc true
- C.
The first line of output is abcd abc false
- D.
The second line of output is abcd abcd true
- 7.Which statements are true about comparing two instances of the same class, given that theequals() and hashCode() methods have been properly overridden? (Choose all that apply.)
- A.
If the equals() method returns true, the hashCode() comparison == might return false
- B.
.If the equals() method returns false, the hashCode() comparison == might return true
- C.
If the hashCode() comparison== returns true, the equals() method must return true
- D.
.If the hashCode() comparison == returns true, the equals() method might return true
- E.
If the hashCode() comparison != returns true, the equals() method might return true
- 8.Given:public static void before() {Set set = new TreeSet();set.add("2");set.add(3);set.add("1");Iterator it = set.iterator();while (it.hasNext())System.out.print(it.next() + " ");}
- A.
The before() method will print 12
- B.
The before() method will print 123
- C.
The before() method will throw an exception at runtime
- D.
The before() method will not compile
- 9.Which collection class(es) allows you to grow or shrink its size and provides indexed access toits elements, but whose methods are not synchronized? (Choose all that apply.)
- A.
.java.util.HashSet
- B.
Java.util.LinkedHashSet
- C.
.java.util.List
- D.
Java.util.ArrayList
- E.
Java.util.Vector
- 10.Int Output = 10; boolean b1 = false; if((b1 == true) && ((Output += 10) == 20)) { System.out.println("We are equal " + Output); } else { System.out.println("Not equal! " + Output); }
- A.
Compilation error, attempting to perform binary comparison on logical data type.
- B.
Compilation and output of "We are equal 10".
- C.
Compilation and output of "Not equal! 20"
- D.
Compilation and output of "Not equal! 10".
- 11.Public void foo( boolean a, boolean b) { if( a ) { System.out.println("A"); /* Line 5 */ } else if(a && b) /* Line 7 */ { System.out.println( "A && B"); } else /* Line 11 */ { if ( !b ) { System.out.println( "notB") ; } else { System.out.println( "ELSE" ) ; } } }
- A.
If a is true and b is true then the output is "A && B"
- B.
If a is true and b is false then the output is "notB"
- C.
If a is false and b is true then the output is "ELSE"
- D.
If a is false and b is false then the output is "ELSE"
- 12.Public void test(int x) { int odd = 1; if(odd) /* Line 4 */ { System.out.println("odd"); } else { System.out.println("even"); } }
- A.
Compilation fails.
- B.
"odd" will always be output.
- C.
"even" will always be output.
- D.
"odd" will be output for odd values of x, and "even" for even values.
- 13.In the following pieces of code, A and D will compile without any error. True or false?A: StringBuffer sb1 = "abcd";B: Boolean b = new Boolean("abcd");C: byte b = 255;D: int x = 0x1234;E: float fl = 1.2;
- A.
True
- B.
False
- 14.What is the result when you compile and run the following code?public class Test { public void method() { for(int i = 0; i < 3; i++) { System.out.print(i); } System.out.print(i); } }
- A.
0122
- B.
0123
- C.
Compilation error
- D.
None of these
- 15.What is displayed when the following code is compiled and executed?String s1 = new String("Test"); String s2 = new String("Test"); if (s1==s2) System.out.println("Same"); if (s1.equals(s2)) System.out.println("Equals");
- A.
Same Equals
- B.
Equals
- C.
Same
- D.
The code compiles, but nothing is displayed upon execution.
- 16.Class PassS { public static void main(String [] args) { PassS p = new PassS(); p.start(); } void start() { String s1 = "slip"; String s2 = fix(s1); System.out.println(s1 + " " + s2); } String fix(String s1) { s1 = s1 + "stream"; System.out.print(s1 + " "); return "stream"; } }
- A.
Slip stream
- B.
Slipstream stream
- C.
Stream slip stream
- D.
Slipstream slip stream
- 17.Class Test { public static void main(String [] args) { int x=20; String sup = (x < 15) ? "small" : (x < 22)? "tiny" : "huge"; System.out.println(sup); } }
- A.
Small
- B.
Tiny
- C.
Huge
- D.
Compilation fails
- 18.Class Test { public static void main(String [] args) { int x= 0; int y= 0; for (int z = 0; z < 5; z++) { if (( ++x > 2 ) || (++y > 2)) { x++; } } System.out.println(x + " " + y); } }
- A.
5 3
- B.
8 2
- C.
8 3
- D.
8 5
- 19.Class Test { static int s; public static void main(String [] args) { Test p = new Test(); p.start(); System.out.println(s); } void start() { int x = 7; twice(x); System.out.print(x + " "); } void twice(int x) { x = x*2; s = x; } }
- A.
7 7
- B.
7 14
- C.
14 0
- D.
14 14
- 20.Int [] a = {1,2,6,"7"};System.out.println(a[3]);
- A.
6
- B.
7
- C.
None of the above
- D.
Option 4
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