Computer Science Contest #0001-____

Computer Science Contest #0506-0 January 21, 2006

Note: Correct responses are based on Java, J2sdk v 1.5.0, from Sun Microsystems, Inc. All provided code segments are intended to be syntactically correct, unless otherwise stated (i. e. error is an answer choice) and any necessary Java 2 Standard Packages have been imported. Ignore any typographical errors and assume any undefined variables are defined as used.

QUESTION 1 xx What is the output? double x = 10/5/2.0; out.println(x); A. 1 B. 4 C. 5.0 D. 1.0 E. 4.0

QUESTION 2 xx What is the output? String s = "Happy New Year"; System.out.println(s.charAt(2)); A. H B. a C. p D. N E. y

QUESTION 3 xx int x = 2; What is the output? switch(x%3){ A. X B. Y C. Z D. XY E. XYZ case 0 : out.print("X"); case 1 : out.print("Y"); break; case 2 : out.print("Z"); }

QUESTION 4 xx Which of the following is a legal reserved word for a 64 bit java data type? A. short B. byte C. int D. char E. double

QUESTION 5 xx What is the output? String s = "12345go12"; s=s.replaceAll("[12345]" ,"x"); A. xgox B. xxxxxgoxx C. xgo12 out.println(s); D. x2345goxx E. error

QUESTION 6 xx What is returned by Math.round(7.83)? A. 8 B. 8.0 C. 7 D. 7.0 E. error

QUESTION 7 xx What of the following statements would not correctly fill < blank 1 > ? Collection x = < blank 1 > ; A. new TreeMap() B. new ArrayList() C. new LinkedList() D. new HashSet() E. new TreeSet() QUESTION 8 xx Which of the following data types could be assigned the value 0 ? A. char B. int C. float D. double E. all of these

QUESTION 9 xx What is the output? boolean one = true; boolean two = true; A. true B. false C. null System.out.println(!(one&&two)); D. one&&two E. true&&false

QUESTION 10 xx Which of the following methods is used to add pairs to a map ? A. add() B. insert() C. put() D. set() E match()

QUESTION 11 xx Which of the following is an Object? A. Char B. float C. Byte D. Int E. None of these CSci 0506-09

QUESTION 12 xx What is the output? char x = 70; System.out.println(x>>3); A. 17 B. 18 C. 35 D. 34 E. 8

QUESTION 13 xx Which of the following interfaces does HashSet implement? A. Set B. SortedSet C. Collection D. A and C only E. A, B, and C QUESTION 14 xx Which of the following sort algorithms was used to write Arrays.sort()if the array to be sorted contains only ints? A. bubble sort B. insertion sort C. selection sort D. merge sort E. quick sort QUESTION 15 xx What is the output? String s = "abc"; String t = s; A. B. muddy abc t = "muddy"; C. ABC D. null E. error out.println(s);

QUESTION 16 xx Integer[][] mat = new Integer[3][3]; What is the output? for( int r=1; r

QUESTION 17 xx WW Which of the following can be used as a test condition for a switch statement? A. short B. int C. long D. A and B only E. A, B, and C

QUESTION 18 xx class A{ What is the output of line 1 ? private int x = 0; public A(){ x =9; } A. 0 public String toString(){ B. 8 return x+" "; C. 9 } D. 9 0 } E. 9 8 class B extends A{ private int x = 0; QUESTION 19 xx public B(){ x=8; } What is the output of line 2 ? public String toString(){

A. 0 0 return x+" "+super.toString(); } B. 8 8 } C. 9 0 //code in main method D. 9 8 A x = new A(); out.println(x); //line 1 E. 8 9 x = new B(); out.println(x); //line 2

QUESTION 20 xx What is the output? String[] list = {"one","two","three"}; for( String e : list) A. B. one two { C. null D. zero E. error list = new String[3]; } out.println(list[0]);

QUESTION 21 xx 092 + 0x92 = A. 184 B. 259 C. 1243 D. 879 E. error

© Charlotte Scroggs http://www.cistests.com written by Stacey Armstrong http://www.apluscompsci.com Page 2 CSci 0506-09 QUESTION 22 xx What is the output? int[] a = {1,4,9,12,67,88}; int pos = Arrays.binarySearch(a,17); A. 0 B. -1 C. -3 D. -5 E. 2 out.println(pos);

QUESTION 23 xx class A Which of the following code statements would correctly fill { so that the A constructor would be complete ? < blank 1 > public A( String val ){ < blank 1 > } A. val = x; public void change( ){x="change it";} public String toString(){ return x; } B. val = " "; private String x; C. x = val; } D. x = " "; class B { public void mystery(A one, A two) { E. x = null; two.change(); QUESTION 24xx one = two; } Assuming that < blank 1 > was filled correctly, what is output public static void main(String args[]){ by line 1 ? B test = new B(); A. change it two A a1 = new A("one"); A a2 = new A("two"); B. two change it test.mystery(a1,a2); C. two two out.println(a1 + " " + a2); //line 1 D. one change it } } E. two it

QUESTION 25 xx int i=0; What is the last value output? for(i=1;i<9;i+=2) A. 5 B. 7 C. 9 D. 11 E. error out.println(i);

QUESTION 26 xx double[] x = What is the output? {Math.pow(2,3),Math.ceil(8.12)}; A. 9.0 B. 9 C. 10 D. 10.0 E. error out.println(x[1]);

QUESTION 27 xx What is the output? String s = "a 1 b 2 c 3"; A. a 1 b 2 c 3 B. -1-2-3 s=s.replaceAll("\\D+","-"); C. ------D. --1---2---3 out.println(s); E. a-1-b-2-c-3

QUESTION 28 xx int x[] = {1,2,3,4,5,6,7,8,9}, sum=0; What is the output? for(Integer i : x){ A. 20 B. 36 if(i%2==0) sum+=i; } C. D. E. error 28 25 out.println(sum);

QUESTION 29 xx What is the output? int x = 7, y = 0; boolean t = ( y>0 & x++>7 | x>7 ); A. true B. 0 C. false D. 1 E. error out.println(t);

QUESTION 30 xx What is the output? out.printf("%04.1f\n",2.1); A. 2.1 B. 2.10 C. 02.1 D. 002.1 E. error

QUESTION 31xx What is returned by fun(2,8)? static int fun( int x, int y) { A. 12 B. 14 C. 16 D. 18 E. 20 if( y == 2)

QUESTION 32 xx return x; else What is returned by fun(8,5)? return fun( x, y - 1) + x; } A. 4 B. 8 C. 16 D. 32 E. error

QUESTION 33 xx

Which of the following statements would fill < blank 1 > so that Chicken can be compared to other Chickens without a cast? A. Comparable B. Comparable