Explore topic-wise MCQs in Engineering.

class HappyGarbage01 { public static void main(String args[]) { HappyGarbage01 h = new HappyGarbage01(); h.methodA(); /* Line 6 */ } Object methodA() { Object obj1 = new Object(); Object [] obj2 = new Object[1]; obj2[0] = obj1; obj1 = null; return obj2[0]; } }

What will be the output of the program?

public class Foo { public static void main(String[] args) { try { return; } finally { System.out.println( "Finally" ); } } }

Which one is a valid declaration of a boolean?

Which one of the following will declare an array and initialize it with five numbers?

Which three are valid declarations of a float?

1. float f1 = -343;
2. float f2 = 3.14;
3. float f3 = 0x12345;
4. float f4 = 42e7;
5. float f5 = 2001.0D;
6. float f6 = 2.81F;

Which is a valid declarations of a String?

Which three are legal array declarations?

1. int [] myScores [];
2. char [] myChars;
3. int [6] myScores;
4. Dog myDogs [];
5. Dog myDogs [7];

Which three are valid declarations of a char?

1. char c1 = 064770;
2. char c2 = 'face';
3. char c3 = 0xbeef;
4. char c4 = u0022;
5. char c5 = ' iface';
6. char c6 = ' uface';

Which is the valid declarations within an interface definition?

public interface Foo { int k = 4; /* Line 3 */
}

1. final int k = 4;
2. public int k = 4;
3. static int k = 4;
4. abstract int k = 4;
5. volatile int k = 4;
6. protected int k = 4;

Which four options describe the correct default values for array elements of the types indicated?

1. int -> 0
2. String -> "null"
3. Dog -> null
4. char -> ' u0000'
5. float -> 0.0f
6. boolean -> true

Which one of these lists contains only Java programming language keywords?

What will be the output of the program?

public class Test { public static void leftshift(int i, int j) { i <<= j; } public static void main(String args[]) { int i = 4, j = 2; leftshift(i, j); System.out.println(i); } }

What will be the output of the program?

class BitShift { public static void main(String [] args) { int x = 0x80000000; System.out.print(x + " and "); x = x >>> 31; System.out.println(x); }
}

Which is a reserved word in the Java programming language?

Which is a valid keyword in java?

What will be the output of the program?

public class CommandArgsThree { public static void main(String [] args) { String [][] argCopy = new String[2][2]; int x; argCopy[0] = args; x = argCopy[0].length; for (int y = 0; y < x; y++) { System.out.print(" " + argCopy[0][y]); } }
}

and the command-line invocation is

> java CommandArgsThree 1 2 3

What will be the output of the program?

public class CommandArgs { public static void main(String [] args) { String s1 = args[1]; String s2 = args[2]; String s3 = args[3]; String s4 = args[4]; System.out.print(" args[2] = " + s2); }
}

and the command-line invocation is

> java CommandArgs 1 2 3 4

public class F0091 { public void main( String[] args ) { System.out.println( "Hello" + args[0] ); } }

What will be the output of the program, if this code is executed with the command line:

> java F0091 world

What will be the output of the program?

public class CommandArgsTwo { public static void main(String [] argh) { int x; x = argh.length; for (int y = 1; y <= x; y++) { System.out.print(" " + argh[y]); } }
}

and the command-line invocation is

> java CommandArgsTwo 1 2 3

In the given program, how many lines of output will be produced?

public class Test { public static void main(String [] args) { int [] [] [] x = new int [3] [] []; int i, j; x[0] = new int[4][]; x[1] = new int[2][]; x[2] = new int[5][]; for (i = 0; i < x.length; i++) { for (j = 0; j < x[i].length; j++) { x[i][j] = new int [i + j + 1]; System.out.println("size = " + x[i][j].length); } } }
}

What will be the output of the program?

public class X { public static void main(String [] args) { String names [] = new String[5]; for (int x=0; x < args.length; x++) names[x] = args[x]; System.out.println(names[2]); }
}

and the command line invocation is

> java X a b

What will be the output of the program?

public class TestDogs { public static void main(String [] args) { Dog [][] theDogs = new Dog[3][]; System.out.println(theDogs[2][0].toString()); }
}
class Dog { }

What will be the output of the program ?

public class Test { public static void main(String [] args) { signed int x = 10; for (int y=0; y<5; y++, x--) System.out.print(x + ", "); }
}

Which will legally declare, construct, and initialize an array?

What will be the output of the program?

class PassA { public static void main(String [] args) { PassA p = new PassA(); p.start(); } void start() { long [] a1 = {3,4,5}; long [] a2 = fix(a1); System.out.print(a1[0] + a1[1] + a1[2] + " "); System.out.println(a2[0] + a2[1] + a2[2]); } long [] fix(long [] a3) { a3[1] = 7; return a3; }
}

What will be the output of the program?

class Equals { public static void main(String [] args) { int x = 100; double y = 100.1; boolean b = (x = y); /* Line 7 */ System.out.println(b); }
}

What will be the output of the program?

class Bitwise { public static void main(String [] args) { int x = 11 & 9; int y = x ^ 3; System.out.println( y | 12 ); }
}

What will be the output of the program?

class SSBool { public static void main(String [] args) { boolean b1 = true; boolean b2 = false; boolean b3 = true; if ( b1 & b2 | b2 & b3 | b2 ) /* Line 8 */ System.out.print("ok "); if ( b1 & b2 | b2 & b3 | b2 | b1 ) /*Line 10*/ System.out.println("dokey"); }
}

What will be the output of the program?

public class X { public static void main(String [] args) { try { badMethod(); System.out.print("A"); } catch (RuntimeException ex) /* Line 10 */ { System.out.print("B"); } catch (Exception ex1) { System.out.print("C"); } finally { System.out.print("D"); } System.out.print("E"); } public static void badMethod() { throw new RuntimeException(); } }

public class ExceptionTest { class TestException extends Exception {} public void runTest() throws TestException {} public void test() /* Point X */ { runTest(); } }

Which two statements are true?

1. Deadlock will not occur if wait()/notify() is used
2. A thread will resume execution as soon as its sleep duration expires.
3. Synchronization can prevent two objects from being accessed by the same thread.
4. The wait() method is overloaded to accept a duration.
5. The notify() method is overloaded to accept a duration.
6. Both wait() and notify() must be called from a synchronized context.

What will be the output of the program?

public class X { public static void main(String [] args) { try { badMethod(); /* Line 7 */ System.out.print("A"); } catch (Exception ex) /* Line 10 */ { System.out.print("B"); /* Line 12 */ } finally /* Line 14 */ { System.out.print("C"); /* Line 16 */ } System.out.print("D"); /* Line 18 */ } public static void badMethod() { throw new RuntimeException(); } }

What will be the output of the program?

public class X { public static void main(String [] args) { try { badMethod(); System.out.print("A"); } catch (Exception ex) { System.out.print("B"); } finally { System.out.print("C"); } System.out.print("D"); } public static void badMethod() { throw new Error(); /* Line 22 */ } }

void start() { A a = new A(); B b = new B(); a.s(b); b = null; /* Line 5 */ a = null; /* Line 6 */ System.out.println("start completed"); /* Line 7 */
} 

class X2 { public X2 x; public static void main(String [] args) { X2 x2 = new X2(); /* Line 6 */ X2 x3 = new X2(); /* Line 7 */ x2.x = x3; x3.x = x2; x2 = new X2(); x3 = x2; /* Line 11 */ doComplexStuff(); } } 

class Boo { Boo(String s) { } Boo() { }
}
class Bar extends Boo { Bar() { } Bar(String s) {super(s);} void zoo() { // insert code here }
}

What will be the output of the program?

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); }
}

What will be the output of the program?

class Test { public static void main(String [] args) { int x=20; String sup = (x < 15) ? "small" : (x < 22)? "tiny" : "huge"; System.out.println(sup); }
}

Which of the following are legal lines of code?

1. int w = (int)888.8;
2. byte x = (byte)1000L;
3. long y = (byte)100;
4. byte z = (byte)100L;

Which two statements are equivalent?

1. 16*4
2. 16>>2
3. 16/2^2
4. 16>>>2

What will be the output of the program?

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"; }
}

What will be the output of the program?

class Test { public static void main(String [] args) { Test p = new Test(); p.start(); } void start() { boolean b1 = false; boolean b2 = fix(b1); System.out.println(b1 + " " + b2); } boolean fix(boolean b1) { b1 = true; return b1; }
}

What will be the output of the program?

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; }
}

Which constructs an anonymous inner class instance?

What will be the output of the program?

public class HorseTest { public static void main (String [] args) { class Horse { public String name; /* Line 7 */ public Horse(String s) { name = s; } } /* class Horse ends */ Object obj = new Horse("Zippo"); /* Line 13 */ Horse h = (Horse) obj; /* Line 14 */ System.out.println(h.name); }
} /* class HorseTest ends */

What will be the output of the program?

public abstract class AbstractTest { public int getNum() { return 45; } public abstract class Bar { public int getNum() { return 38; } } public static void main (String [] args) { AbstractTest t = new AbstractTest() { public int getNum() { return 22; } }; AbstractTest.Bar f = t.new Bar() { public int getNum() { return 57; } }; System.out.println(f.getNum() + " " + t.getNum()); }
}

What allows the programmer to destroy an object x?

What will be the output of the program?

public class TestObj { public static void main (String [] args) { Object o = new Object() /* Line 5 */ { public boolean equals(Object obj) { return true; } } /* Line 11 */ System.out.println(o.equals("Fred")); }
}

What will be the output of the program?

class Exc0 extends Exception { } class Exc1 extends Exc0 { } /* Line 2 */
public class Test { public static void main(String args[]) { try { throw new Exc1(); /* Line 9 */ } catch (Exc0 e0) /* Line 11 */ { System.out.println("Ex0 caught"); } catch (Exception e) { System.out.println("exception caught"); } } }