You Are On Multi Choice Question Bank SET 1642
82101. What two statements are true about properly overridden hashCode() and equals() methods? hashCode() doesn't have to be overridden if equals() is. equals() doesn't have to be overridden if hashCode() is. hashCode() can always return the same value, regardless of the object that invoked it. equals() can be true even if it's comparing different objects.
82102. Which two statements are true about comparing two instances of the same class, given that the equals() and hashCode() methods have been properly overridden? If the equals() method returns true, the hashCode() comparison == must return true. If the equals() method returns false, the hashCode() comparison != must return true. If the hashCode() comparison == returns true, the equals() method must return true. If the hashCode() comparison == returns true, the equals() method might return true.
82103. x = 0; if (x1.hashCode() != x2.hashCode() ) x = x + 1; if (x3.equals(x4) ) x = x + 10; if (!x5.equals(x6) ) x = x + 100; if (x7.hashCode() == x8.hashCode() ) x = x + 1000; System.out.println("x = " + x); and assuming that the equals() and hashCode() methods are properly implemented, if the output is "x = 1111", which of the following statements will always be true?
82104. Which of the following are true statements? The Iterator interface declares only three methods: hasNext, next and remove. The ListIterator interface extends both the List and Iterator interfaces. The ListIterator interface provides forward and backward iteration capabilities. The ListIterator interface provides the ability to modify the List during iteration. The ListIterator interface provides the ability to determine its position in the List.
82106. Suppose that you would like to create an instance of a new Map that has an iteration order that is the same as the iteration order of an existing instance of a Map. Which concrete implementation of the Map interface should be used for the new instance?
82107. Which class does not override the equals() and hashCode() methods, inheriting them directly from class Object?
82108. Which collection class allows you to grow or shrink its size and provides indexed access to its elements, but whose methods are not synchronized?
82109. You need to store elements in a collection that guarantees that no duplicates are stored and all elements can be accessed in natural order. Which interface provides that capability?
82115. Isolated area in which root is denuded of bone and covered by mucoperiosteum with intact marginal alveolar bone is knows as
82116. 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); } }
82117. 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); } }
82118. 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); } }
82119. 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 ); } }
82120. 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"); } }
82121. What will be the output of the program? class SC2 { public static void main(String [] args) { SC2 s = new SC2(); s.start(); } void start() { int a = 3; int b = 4; System.out.print(" " + 7 + 2 + " "); System.out.print(a + b); System.out.print(" " + a + b + " "); System.out.print(foo() + a + b + " "); System.out.println(a + b + foo()); } String foo() { return "foo"; } }
82122. 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 = x2; s = x; } }
82123. What will be the output of the program? class Two { byte x; } class PassO { public static void main(String [] args) { PassO p = new PassO(); p.start(); } void start() { Two t = new Two(); System.out.print(t.x + " "); Two t2 = fix(t); System.out.println(t.x + " " + t2.x); } Two fix(Two tt) { tt.x = 42; return tt; } }
82124. What will be the output of the program? class BoolArray { boolean [] b = new boolean[3]; int count = 0; void set(boolean [] x, int i) { x[i] = true; ++count; } public static void main(String [] args) { BoolArray ba = new BoolArray(); ba.set(ba.b, 0); ba.set(ba.b, 2); ba.test(); } void test() { if ( b[0] && b[1] | b[2] ) count++; if ( b[1] && b[(++count - 2)] ) count += 7; System.out.println("count = " + count); } }
82125. 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.printIn(i); } }
82126. import java.awt.; class Ticker extends Component { public static void main (String [] args) { Ticker t = new Ticker(); / Missing Statements ? / } } which two of the following statements, inserted independently, could legally be inserted into missing section of this code? boolean test = (Component instanceof t); boolean test = (t instanceof Ticker); boolean test = t.instanceof(Ticker); boolean test = (t instanceof Component);
82127. Which of the following are legal lines of code? int w = (int)888.8; byte x = (byte)1000L; long y = (byte)100; byte z = (byte)100L;
82130. import java.awt.Button; class CompareReference { public static void main(String [] args) { float f = 42.0f; float [] f1 = new float[2]; float [] f2 = new float[2]; float [] f3 = f1; long x = 42; f1[0] = 42.0f; } } which three statements are true? f1 == f2 f1 == f3 f2 == f1[1] x == f1[0] f == f1[0]
82132. 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; } }
82133. 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; } }
82134. 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"; } }
82135. 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); } }
82136. 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); } }
82142. Which two of the following methods are defined in class Thread? start() wait() notify() run() terminate()
82143. Which three guarantee that a thread will leave the running state? yield() wait() notify() notifyAll() sleep(1000) aLiveThread.join() Thread.killThread()
82148. Assume the following method is properly synchronized and called from a thread A on an object B: wait(2000); After calling this method, when will the thread A become a candidate to get another turn at the CPU?
Powered By:Omega Web Solutions© 2002-2017 Omega Education PVT LTD...Privacy | Terms And Conditions