Java 6 Test
Pearlox Corp.
Java 6 Test
- 1.
What will be the output if you compile and run the following code ?(Choose the correct answer)public class test { public static void main(String args[]) { String str1="abc"; String str2="def"; String str3=str1.concat(str2); str1.concat(str2); System.out.println(str1); }}
- A.
Abc
- B.
Def
- C.
Abcabc
- D.
Abcdef
- E.
Defabc
Correct Answer
A. Abc -
- 2.
The number of characters in an object of a class String is given by(Choose the correct answer)
- A.
The member variable called size
- B.
The member variable called length
- C.
The method size() returns the number of characters.
- D.
The method length() returns the number of characters.
- E.
The method getSize() returns the number of characters.
Correct Answer
D. The method length() returns the number of characters. -
- 3.
Which method defined in Integer class can be used to convert an Integer object to primitive int type.(Choose the correct answer)
- A.
ValueOf
- B.
IntValue
- C.
GetInt
- D.
GetInteger
- E.
ToInt
Correct Answer
B. IntValue -
- 4.
Which are valid Java keywords.(Choose all that apply)
- A.
Distinct
- B.
Synchronized
- C.
Volatile
- D.
Goto
- E.
Construct
Correct Answer(s)
B. Synchronized
C. Volatile
D. Goto -
- 5.
What is the number of bytes used by the primitive type long. (Select the best answer)
- A.
8
- B.
16
- C.
32
- D.
64
- E.
128
Correct Answer
D. 64 -
- 6.
What is the name of the Collection interface used to represent elements in a sequence (in a particular order). (Choose the correct answer)
- A.
Collection
- B.
Set
- C.
List
- D.
Map
- E.
HashMap
Correct Answer
C. List -
- 7.
Which of the following statements about arrays are true.(Choose all that apply)
- A.
Arrays in Java are objects.
- B.
It is not possible to assign one array to another.
- C.
Array elements are indexed from 1 to size of the array.
- D.
If a method tries to access an array element beyond its range, a compile warning is generated.
- E.
Arrays size must be specified at creation time.
Correct Answer(s)
A. Arrays in Java are objects.
E. Arrays size must be specified at creation time. -
- 8.
What will be the output if you compile and run the following code ?public class Main {public static void main(String[] args) { int i1=1; switch(i1){ case 1: System.out.println("one"); case 2: System.out.println("two"); case 3: System.out.println("three");}}}
- A.
One two three
- B.
One
- C.
One two
- D.
Compile error.
- E.
None of the above
Correct Answer
A. One two three -
- 9.
What will be the output if you compile and run the following code ?public class Main { public static void main(String[] args) { char c = 'a'; switch(c){ case 1: System.out.println("one");break; case 'a': System.out.println("two");break; case 3: System.out.println("three"); } }}
- A.
One two three
- B.
One
- C.
Two
- D.
Three
- E.
Compile error.
Correct Answer
B. One -
- 10.
What will be the output if you compile and run the following code ?public class Main { public static void main(String[] arg) { method1(arg); } public void method1(String... arguments) { System.out.println(arguments); }}
- A.
Cannot make a static reference to the non-static method method1.
- B.
Compile error method main is not correct
- C.
Compile error method method1 is not correct
- D.
Method1 must be declared with String not String...
- E.
This code compiles and run without errors.
Correct Answer
A. Cannot make a static reference to the non-static method method1. -
- 11.
What will be the output if you compile and run the following code ?public class Main{ private static int i; public static void main(String[] args){ System.out.println(i); }}
- A.
Error, Variable i may not have been initialized
- B.
0
- C.
1
- D.
Null
- E.
None of the above
Correct Answer
B. 0 -
- 12.
What will be the output if you compile and run the following code ?public class Main { public static void main(String[] args){ int vest[]=new int[]{1,2,3}; System.out.println(vest[1]); }}
- A.
1
- B.
Error vest is referenced before it is initialized
- C.
2
- D.
Error: size of array must be defined
- E.
None of the above
Correct Answer
C. 2 -
- 13.
What will be the output if you compile and run the following code ?public class Test { public static void main(String[] arg){ int anar[]=new int[5]; System.out.println(anar[0]); }}
- A.
Error: anar is referenced before it is initialized
- B.
Null
- C.
0
- D.
5
- E.
4
Correct Answer
C. 0 -
- 14.
What will be the output if you compile and run the following code ?abstract class Super { abstract void amethod(); static int i;}public class Test extends Super { public static void main(String... args){ int[] arr = new int[5]; for(i=0;i < arr.length;i++) System.out.println(arr[i]); }}
- A.
0 1 2 3 4 is printed
- B.
Compile error, arr is used before it is initialized
- C.
Compile error, Test must be declared abstract
- D.
ArrayIndexOutOfBoundes Exception
- E.
None of the above.
Correct Answer
C. Compile error, Test must be declared abstract -
- 15.
What will be the output if you compile and run the following code ?int i=1; switch (i) { case 0: System.out.println("number"); break; case 1: System.out.println("one"); case 5: System.out.println("two");case 10: System.out.println("three"); default: System.out.println("default"); }
- A.
One
- B.
One, default
- C.
One, two, three, default
- D.
Default
- E.
Two
Correct Answer
C. One, two, three, default -
- 16.
What will be the output if you compile and run the following code ?int h=15;switch (h) { default: System.out.println("default"); case 20: System.out.println("20"); break; case 21: System.out.println("21"); case 22: System.out.println("22"); }
- A.
Default
- B.
Default, 20
- C.
20, 21
- D.
No output is displayed
- E.
Compiler error default must be defined last.
Correct Answer
B. Default, 20 -
- 17.
Which of the following statements are correct ?
- A.
Methods cannot be overriden to be more restrictive for example private
- B.
Static methods cannot be overloaded
- C.
Private methods cannot be overloaded
- D.
Abstract methods cannot be overriden in subclasses.
- E.
Final methods cannot be overriden in subclasses.
Correct Answer(s)
A. Methods cannot be overriden to be more restrictive for example private
E. Final methods cannot be overriden in subclasses. -
- 18.
Which of the following methods can be legally inserted in place of the comment //Insert Method Here ..class Main{ public void method1(int i) { }}public class Sub extends Main{ public static void main(String[] args){ } //Insert Method Here ..}
- A.
Void method1(int k) throws Exception {}
- B.
Void method1(long i)throws Exception {}
- C.
void method1(long i){}
- D.
Public void method1(int j) throws Exception {}
- E.
Public void method1(double d) throws Exception {}
Correct Answer(s)
B. Void method1(long i)throws Exception {}
C. void method1(long i){}
E. Public void method1(double d) throws Exception {} -
- 19.
What will be the output if you compile and run the following code ?String str=new String("honey");int begin=1;int end=3;System.out.println(str.substring(begin,end));
- A.
Hon
- B.
Ho
- C.
On
- D.
Runtime Exception is thrown
- E.
None of the above
Correct Answer
C. On -
- 20.
Given the following declarationsString s1=new String("1")String s2=new String("2");String s3=new String("true");String s3=new String("false");Which of the following are legal operations?
- A.
S3=s1 + s2;
- B.
S3=s1-s2;
- C.
S3=s1 & s2;
- D.
S3=s1 && s2
- E.
S3=s3 && s4
Correct Answer
A. S3=s1 + s2; -
- 21.
What will happen when you attempt to compile and run the following code?class TestRunnable implements Runnable { int k = 0; public int run() { while (true) { k++; System.out.print("k=" + k); } return 50; }}
- A.
It will compile fine.
- B.
It will not compile.
- C.
The code will compile but throws an exception at runtime.
- D.
Comipler errors because while cannot take a parameter of true.
- E.
None of the above.
Correct Answer
B. It will not compile. -
- 22.
Which of the following statements about this code are true?class Testing extends Thread{ public void run(){ for(int i =0; i < 2; i++){ System.out.println(i); } } }public class Sub{ public static void main(String[] args){ Sub m = new Sub(); m.go(new Testing()); } public void go(Testing t){ t.start(); } }
- A.
This program compiles and run fine, but it has no output.
- B.
Compiler error, class Testing has no start method
- C.
Compiles fine and output 0 followed by 1
- D.
Compiles fine but fails at runtime.
- E.
Compiler error, class Testing doesnt provide legal override for method run.
Correct Answer
C. Compiles fine and output 0 followed by 1 -
- 23.
What will happen if you attempt to compile and run the following code?.public class Main { static int j = 20; public static void main(String[] args) { int i = 10; Main m = new Main(); m.m1(i); System.out.println(i); System.out.println(j); } public void m1(int x) { x = x * 2; j = j * 2; }}
- A.
Compiler error, static access from non static context.
- B.
20 and 40
- C.
10 and 40
- D.
10 and 20
- E.
20 and 20
Correct Answer
C. 10 and 40 -
- 24.
What will happen if you attempt to compile and run the following code?.public class Main { public static void main(String[] args) { Main m = new Main(); m.m1(); } public void m1() { int ii = 012; System.out.println(ii); }}.............
Correct Answer
10 - 25.
You have a requirement to create a class that will store unique object elements. And you do not need to sort these elements.Which interface might be most suitable to meet your requirement?
- A.
Set
- B.
List
- C.
Map
- D.
ArrayList
- E.
Collection
Correct Answer
A. Set -
- 26.
What will happen if you attempt to compile and run the following code?.public class Main { private int ii; public static void main(String[] args) { Main m = new Main(); m.m1(); } public static void m1() { System.out.println(ii); }}
- A.
A value of 0 will be printed to the standard output
- B.
Nothing will be printed
- C.
Compiler error occured
- D.
A Compiler error occured complaining of the scope of variable ii
- E.
Runtime exception is thrown.
Correct Answer
C. Compiler error occured -
- 27.
Which declares a valid main method. (Choose all that apply)
- A.
Public static void Main(String[] args)
- B.
Static void main(String args...)
- C.
public static void main(String... args)
- D.
Public void main(String args)
- E.
Public static void main(String arguments[])
Correct Answer(s)
C. public static void main(String... args)
E. Public static void main(String arguments[]) -
- 28.
Given the following declarations, which of the assignments given below would compile.(Choose all that apply)int k = 20;boolean b = true;float f = 2.5F;double d = 2.5;
- A.
B = (boolean) k;
- B.
F = d;
- C.
D = k;
- D.
K = (int)5.5D;
- E.
F = 2.8;
Correct Answer(s)
C. D = k;
D. K = (int)5.5D; -
- 29.
Which defines a legal method declaration ?(Choose all that apply)
- A.
Void m1() throws Exception{}
- B.
Void m2(int) throw Exception{}
- C.
Private m3() {}
- D.
Volatile m4() throws IOException{}
- E.
Private synchronized void m5() throws Exception {}
Correct Answer(s)
A. Void m1() throws Exception{}
E. Private synchronized void m5() throws Exception {} -
- 30.
Which are legal identifier names in Java. (Choose all that apply)
- A.
True
- B.
$a_
- C.
1a
- D.
A1
- E.
_this_is_a_lengthy_variable_name_in_java_
Correct Answer(s)
B. $a_
D. A1
E. _this_is_a_lengthy_variable_name_in_java_ -
- 31.
void method() { }Which of the following declares a legal override of this method in a sub class.(Choose all that apply)
- A.
Void method() { }
- B.
Int method() { return 0;}
- C.
Void method(int i) { }
- D.
private void method() { }
- E.
Protected void method() { }
Correct Answer(s)
B. Int method() { return 0;}
D. private void method() { }
E. Protected void method() { } -
- 32.
Which keyword when applied on a method indicates that only one thread can execute this method at a time. (Choose the correct answer)
- A.
Transient
- B.
Volatile
- C.
Synchronized
- D.
Native
- E.
Static
Correct Answer
C. Synchronized -
- 33.
Which of these statements are true. (Choose all that apply)
- A.
For each try block there must be at least one catch block defined
- B.
A try block may be followed by any number of finally blocks
- C.
A try block must be followed by at least one finally or catch block
- D.
If both catch and finally blocks are defined, catch block must appear before finally
- E.
A try block may be defined inside a catch block
Correct Answer(s)
C. A try block must be followed by at least one finally or catch block
D. If both catch and finally blocks are defined, catch block must appear before finally
E. A try block may be defined inside a catch block -
- 34.
What gets printed when the following program is compiled and run? (Choose the correct answer)class Main { public static void main(String[] args) { int i; do { i++; } while(i < 0); System.out.println(i); }}
- A.
The program does not compile as i is not initialized
- B.
The program compiles but does not run.
- C.
The program compiles and runs but does not print anything
- D.
The program prints 0
- E.
The program prints 1
Correct Answer
A. The program does not compile as i is not initialized -
- 35.
What gets printed when the following program is compiled and run? (Choose the correct answer)class Main { static int i; public static void main(String... args) { while (i < 0) { i--; } System.out.println(i); }}
- A.
The program does not compile as i is not initialized
- B.
The program compiles but does not run
- C.
The program compiles and runs but does not print anything
- D.
The program prints 0
- E.
The program prints 1
Correct Answer
D. The program prints 0 -
- 36.
What gets printed when the following program is compiled and run? public class Main { public void m1(Object o) { System.out.println("Object"); } public void m1(String s) { System.out.println("String"); } public static void main(String args[]) { Main m = new Main(); m.m1(null); }}
- A.
The code does not compile
- B.
The code compiles fine and prints "Object"
- C.
The code compiles fine and prints "String"
- D.
The code throws an Exception at Runtime
- E.
The output cannot be determined
Correct Answer
C. The code compiles fine and prints "String" -
- 37.
What kind of thread is the Garbage collector thread?
- A.
Daemon thread
- B.
Kernel thread
- C.
User thread
- D.
Worker thread
- E.
Hyper threaed
Correct Answer
A. Daemon thread -
- 38.
What kind of objects is StringBuffer ?
- A.
Reference object
- B.
Primitive object
- C.
Mutable object
- D.
Immutable object
- E.
Oriented object
Correct Answer
C. Mutable object -
- 39.
What Locale object represent?
- A.
Geographical
- B.
Political
- C.
Cultural region
- D.
Language
- E.
All the above
Correct Answer
E. All the above -
- 40.
What is the best way to findout the time/memory consuming process?
- A.
Using profiler
- B.
Using logger
- C.
Using debuger
- D.
Using sysstat
- E.
Using analizer
Correct Answer
A. Using profiler -
- 41.
What is the singleton access modifier ?
- A.
Private
- B.
Public
- C.
Protected
- D.
Default
Correct Answer
A. Private -
- 42.
Class C {public static void main(String[] args) {int[]a1[]=new int[3][3]; //3int a2[4]={3,4,5,6}; //4int a2[5]; //5}}What is the result of attempting to compile and run the program ?.
- A.
Compiletime error at lines 3,4,5
- B.
Compiltime error at line 4,5
- C.
Compiletime error at line 3
- D.
Runtime Exception
- E.
None of the above
Correct Answer
B. Compiltime error at line 4,5 -
- 43.
interface I{void f1(); // 1public void f2(); // 2protected void f3(); // 3private void f4(); // 4}which lines generate compile time errors?
- A.
Compiletime error at lines 1,2,3,4
- B.
Compiletime error at line 3
- C.
Compiletime error at line 1
- D.
Compiletime error at lines 3,4
- E.
None of the above
Correct Answer
D. Compiletime error at lines 3,4 -
- 44.
class C{int i;public static void main (String[] args) {int i; //1private int a = 1; //2protected int b = 1; //3public int c = 1; //4System.out.println(a+b+c); //5}}
- A.
Compiletime error at lines 1,2,3,4,5
- B.
Compiletime error at lines 2,3,4,5
- C.
Compiletime error at lines 2,3,4
- D.
Prints 3
- E.
None of the above
Correct Answer
B. Compiletime error at lines 2,3,4,5 -
- 45.
class C {public static void main (String[] a1) {System.out.print(a1[1] + a1[2] + a1[3]);}}What is the result of attempting to compile and run the program? java command A B C
- A.
Prints: ABC
- B.
Prints BC and Runtime Exception
- C.
Prints: BCD
- D.
Runtime Exception
- E.
None of the above
Correct Answer
B. Prints BC and Runtime Exception -
- 46.
class C{static int s;public static void main(String a[]){C obj=new C();obj.m1();System.out.println(s);}void m1();{int x=1;m2(x);System.out.println(x+"");}void m2(int x){x=x*2;s=x;}}
- A.
Prints 1,2
- B.
Prints 2,0
- C.
Prints 2,2
- D.
Compile time error
- E.
None of the above
Correct Answer
A. Prints 1,2 -
- 47.
class C {public static void main(String[] args) {int i1=1;switch(i1){case 1:System.out.println("one");case 2:System.out.println("two");case 3:System.out.println("three");}}}What is the result of attempting to compile and run the program?
- A.
Prints one two three
- B.
Prints one
- C.
Compile time error
- D.
Runtime exception
- E.
None of the above
Correct Answer
A. Prints one two three -
- 48.
Each element must be unique Duplicate elements must not replace old elements. Elements are not key/value pairs.Accessing an element can be almost as fast as performing a similar operation on an array.Which of these classes provide the specified features?
- A.
LinkedList
- B.
TreeMap
- C.
HashMap
- D.
HashSet
- E.
None of the above
Correct Answer
D. HashSet -
- 49.
class C1{static interface I{static class C2{}}public static void main(String a[]){C1.I.C2 ob1=new C1.I.C2();System.out.println("object created");}}What is the result of attempting to compile and run the program?
- A.
Prints object created
- B.
Compile time error
- C.
Runtime Excepion
- D.
None of the above
Correct Answer
A. Prints object created -
- 50.
class C1{static class C2{static int i1;}public static void main(String a[]){System.out.println(C1.C2.i1);}}What is the result of attempting to compile and run the program?
- A.
Prints 0
- B.
Compile time error
- C.
Runtime exception
- D.
None of the above
Correct Answer
A. Prints 0 -
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Jan 11, 2013Quiz Edited by
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Apr 20, 2010Quiz Created by
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