Computer Science: Application Multiple Choice
1. True or false: If an array is already sorted, Linear Search / Sequential Search is more efficient than Binary Search.
|
True |
|
False |
2. What must be true before performing a binary search?
|
The elements must be sorted. |
|
It can only contain binary values. |
|
The elements must be some sort of number (i.e. int, double, Integer) |
|
There are no necessary conditions. |
3. Which of the following functions is a proper implementation of binary search?
|
public static int binarySearch(int[] array, int key) { int n = array.length; int first = 0; int last = n - 1; int middle = (first + last)/2;
while( first <= last ) { if ( array[middle] < key ) { first = middle + 1; } else if ( array[middle] == key ) { return (middle + 1); } else { last = middle - 1; }
middle = (first + last)/2; } return -1; } |
|
public static int binarySearch(int[] array, int key) { int n = array.length; int first = 0; int last = n - 1; int middle = (first + last)/2;
while( first <= last ) { if ( array[middle] < key ) { first = middle + 1; } else if ( array[middle] == key ) { return middle; } else { last = middle - 1; }
middle = (first + last)/2; } return -1; } |
|
public static int binarySearch(int[] array, int key) { n = array.length; first = 0; last = n - 1; middle = (first + last)/2;
while( first <= last ) { if ( array[middle] < key ) { first = middle + 1; } else if ( array[middle] == key ) { System.out.println(key + " found at index " + middle); } else { last = middle - 1; } middle = (first + last)/2; } System.out.println("Key not found!") } |
|
public static int binarySearch(int[] array, int key) { int n = array.length; int first = 0; int last = n - 1; int middle = (first + last)/2;
while( first <= last ) { if ( array[middle] < key ) { first = middle + 1; } else if ( array[middle] == key ) { int result = middle; } else { last = middle - 1; }
middle = (first + last)/2; } } |
4. Given this array:
1 2 4 5 6 7 8 12 14 21 22 42 53
How many comparisons are required to find 42 using the Binary Search?
|
3 |
|
2 |
|
10 |
|
5 |
5. Given this array:
1 2 4 5 6 7 8 12 14 21 22 42 53
How many comparisons are required to find 42 using the Linear Search / Sequential Search?
|
3 |
|
2 |
|
12 |
|
5 |
6. BMO the robot is programming a new game called “Open the box!” You give him a number and he tries to open a numbered box. He’s using Binary Search to accomplish this. Unfortunately, the boxes are not sorted. They are in the following order:
1 3 6 9 14 10 21
Which box can NEVER be found using binary search?
|
9 |
|
6 |
|
14 |
|
10 |
7. We are searching for an int key in a sorted int array that has n elements. Under what circumstances will Linear Search / Sequential Search be more efficient than Binary Search?
|
key is the last element in the array |
|
key is in the middle of the array |
|
n is very large |
|
key is the first element in the array |
|
key does not exist in the array |
8. What is the largest number of comparisons needed to perform a binary search on an array with 42 elements?
|
2 |
|
5 |
|
6 |
|
41 |
|
42 |
9. What approach does MergeSort use?
|
divide and conquer |
|
iterative |
|
search and swap |
|
search and insert |
10. Which sorting method is implemented below?
public int[] array;
public int[] tempArr;
public int length;
public void sort(int[] inputArr)
{
array = inputArr;
length = inputArr.length;
tempArr = new int[length];
doSort(0, length - 1);
}
private void doSort(int lowerIndex, int higherIndex)
{
if (lowerIndex < higherIndex)
{
int middle = lowerIndex + (higherIndex - lowerIndex) / 2;
doSort(lowerIndex, middle);
doSort(middle + 1, higherIndex);
doSomething(lowerIndex, middle, higherIndex);
}
}
private void doSomething(int lowerIndex, int middle, int higherIndex)
{
for (int i = lowerIndex; i <= higherIndex; i++)
{
tempArr[i] = array[i];
}
int i = lowerIndex;
int j = middle + 1;
int k = lowerIndex;
while (i <= middle && j <= higherIndex)
{
if (tempArr[i] <= tempArr[j])
{
array[k] = tempArr[i];
i++;
}
else {
array[k] = tempArr[j];
j++;
}
k++;
}
while (i <= middle)
{
array[k] = tempArr[i];
k++;
i++;
}
}
|
Selection sort |
|
Insertion sort |
|
Mergesort |
|
Binary search |
|
Sequential search / Linear search |
11. Given the method implemented above, how many times will the method doSort be called if an array agescontains the values
[23, 12, 9, 46, 34]
and sort(ages) is called?
|
12 |
|
6 |
|
9 |
|
5 |
|
15 |
12. How are Selection Sort and Insertion Sort different?
I – Selection Sort is always faster than Insertion Sort
II – Insertion Sort is always faster than Selection Sort
III – When Selection Sort places an element into the sorted part of the array, that element is in its final position, whereas Insertion Sort may move the element later if it finds a smaller element. Selection Sort builds up an absolutely sorted array as it goes while Insertion Sort builds up a relatively sorted array as it goes.
IV – Insertion Sort is faster if the array is already sorted or close to sorted
|
I only |
|
II only |
|
II and IV |
|
II and III |
|
III and IV |
13. What is the correct pseudocode for Insertion Sort?
|
If there are at least two elements in the collection Partition the collection Insertion sort the left collection Insertion sort the right collection |
|
If there is more than one element in the collection Break the collection into two halves Insertion sort the left half Insertion sort the right half Compare the two halves Merge the two subcollections into a sorted collection |
|
Start with the first element and sort it with itself While there is a next element Compare the next unsorted element with the sorted elements Insert the element into the correct position in the sorted elements |
|
While there are unsorted numbers Find the smallest unsorted number Insert the element at the end of the sorted elements |
14. For this array of numbers:
[1, 2, 3, 4, 5]
How many comparisons are made using Selection Sort?
|
5 |
|
10 |
|
1 |
|
6 |
|
11 |
15. Which of the following sorting algorithms use recursion?
|
Selection Sort |
|
Insertion Sort |
|
Merge Sort |
16. What are the drawbacks of using mergesort?
|
It has no drawbacks. |
|
It only works on arrays. |
|
There are special cases where it runs very slowly. |
|
It uses more memory. |
17. Suppose we have a sorted list with n elements. We decide to perform an insertion sort on this already sorted set. How many comparisons will the sort make?
|
n - 1 |
|
n |
|
n (n - 1) |
|
n + 1 |
18. What must be true in order to sort objects?
|
They must be wrapper classes of primitives (Integer, Double, etc.) |
|
They must be Comparable. |
|
At least one instance variable must be a primitive. |
|
They must be Strings |
|
Objects are not sortable, only primitives are sortable. |
19. Consider the following recursive function:
public int mystery(int n)
{
if(n == 0)
{
return 2;
}
else
{
return 2 * mystery(n - 1);
}
}
How many times will the function mystery be called if we call mystery(5) (be sure to include the first call mystery(5))
|
5 |
|
6 |
|
4 |
|
10 |
|
The recursion will go on forever because there is no base case. |
Question: 1
You are working as a programmer on a new game called Dessert Demolish at the well known game studio Queen. You are asked to write a method that searches a String[][] for a given dessert name. The problem specification does not indicate what your method should do if there are multiple Strings in the String[][]with the same value. Which of the following actions would be best?
|
The method should be written on the assumption that there is only one dessert String in the String[][] with the passed value. |
|
The method should be written so as to return the index of every occurrence of the passed dessert String value. |
|
The specification should be modified to indicate what should be done if there is more than one index of the passed dessert String. |
|
The method should be written to output a message if more than one larger value is found. |
|
The method should be written to delete all subsequent instances of the dessert String from the String[][] |
CHECK
Question: 2
Considering the inheritance hierarchy
public class Message
{
...
}
public class Text extends Message
{
...
}
public class Email extends Message
{
...
}
public class Letter extends Message
{
...
}
Which of the following statements are true about the above classes?
I – The Text class can have private instance variables that are not in its sibling or parent classes. II – If the Message class has a private variable, none of it’s children classes can access the variable directly. III – Each of the 4 classes can have a method called toString, whose code is the exact same throughout all of them. IV – The Text, Email, and Letter class all inherit the contructors of the Message class
|
I only |
|
III only |
|
I and II |
|
I, II, and III |
|
I, II, III, and IV |
CHECK
Question: 3
Given the following class:
public class Dog
{
public String name;
private String breed;
private int age;
public Dog(String name, String breed, int age)
{
...
}
public String getBreed()
{
return breed;
}
public int getAge()
{
return age;
}
}
Which of the following represents the correct implementation of the Dog’s constructor method?
|
name = name; breed = breed; age = age; |
|
myName = name; myBreed = breed; myAge = age; |
|
this.name = name; this.breed = breed; this.age = age; |
|
this.name = name; this.breed = getBreed(); this.age = getAge(); |
|
return new Dog(name, breed, age); |
CHECK
Question: 4
Given the following method.
// Precondition: myArray is not empty
// Postcondition: Returns max int value found in myArray
public static int findMax(int[] myArray)
{
int max = // Some value.
for (int i = 0; i < myArray.length; i++)
{
if (myArray[i] > max)
{
max = myArray[i];
}
}
return max;
}
Which of following are correct starting values for the int max variable.
- I Integer.MIN_VALUE
- II Integer.MAX_VALUE
- III myArray[0]
- IV 9999
|
I Only |
|
IV Only |
|
I and III |
|
II and IV |
|
II Only |
CHECK
Question: 5
What is the largest base-10 integer that can be represented by 8 bits?
|
8 |
|
256 |
|
16 |
|
15 |
|
255 |
CHECK
Question: 6
public abstract class Quadrilateral
{
private String labels;
public Quadrilateral(String labels)
{
this.labels = labels;
}
public String getLabels()
{
return labels;
}
public abstract int area();
}
Which of the following statements about the Quadrilateral class are true?
I – Subclasses of the class must implement the the area method. II – No instances of the class can be created. This class cannot be instantiated. III – The area method is missing an implementation. This code will not compile. IV – The getLabels method is not abstract. V – Subclasses of Quadrilateral will not directly inherit the constructor.
|
IV only |
|
II only |
|
I and III |
|
II, IV, and V |
|
I, II, IV, and V |
CHECK
Question: 7
When must the super keyword be called in a subclass constructor?
|
The super keyword must always be called in the subclass constructor. |
|
The super keyword never has to be called in the subclass constructor. |
|
The super keyword must be called in the subclass constructor if the parent class is abstract. |
|
The super keyword must be called in the subclass constructor if the parent class does not have a constructor with no parameters. |
|
The super keyword must be called in the subclass constructor if the parent is the Object class |
CHECK
Question: 8
Considering the following code segments: Main.java
public class Main
{
public void run()
{
MyClass myInstance = new MyClass();
MyOtherClass myOtherInstance = new MyOtherClass();
/* more code here */
}
}
MyClass.java
public class MyClass
{
public MyClass()
{/* code */}
public void someMethod()
{/* code */}
}
MyOtherClass.java
public class MyOtherClass extends MyClass
{
public MyOtherClass()
{/* code */}
public void someOtherMethod()
{/* code */}
}
which of the following method calls would error if placed inside the /* more code here */ comment inside the main method. You may assume that none of the implementations of the methods will throw a runtime error.
I. myInstance.someMethod();
II. myInstance.someOtherMethod();
III. myOtherInstance.someMethod();
IV. myOtherInstance.someOtherMethod();
|
All of them |
|
None of them |
|
III Only |
|
I and IV |
|
II Only |
CHECK
Question: 9
Which of the following is true about a method that is overriding another method?
|
A method with the same name as another method but with different types for the parameters |
|
A method with the same name as another method but with a different number of parameters |
|
A method with the same precondition as another method |
|
A method with the same name and parameter list as an inherited method |
|
None of these are true |
CHECK
Question: 10
Given this code segment:
public void myMethod(String[] array)
{
for(i = 0; i < array.length; i++)
{
System.out.println(array[i]);
}
}
Identify the bug in the code.
|
Arrays do not have a length property |
|
There will be an index out of bounds exception |
|
The code results in a null pointer exception |
|
You cannot initialize variables inside a for loop statement |
|
Variable i was not declared |
CHECK
Question: 11
What would be printed to the console with the following expression:
System.out.println( 5 + 4 + “string” + 7 + 7 );
|
9string14 |
|
54string77 |
|
9string77 |
|
54string14 |
|
This code will result in an error |
CHECK
Question: 12
What would be printed to the console with the following expression:
System.out.println( (5 + 4) + “string” + ( 7 + 7 ) );
|
9string14 |
|
54string77 |
|
9string77 |
|
54string14 |
|
This code will result in an error |
CHECK
Question: 13
What is the output of the following code:
ArrayList<Integer> numbers = new ArrayList<Integer>();
numbers.add(1);
numbers.add(0, 2);
numbers.add(1, 3);
numbers.add(4);
numbers.remove(2);
numbers.add(3, 5);
numbers.remove(2);
|
[2, 3, 4] |
|
[2, 3, 5] |
|
[1, 2, 5] |
|
[1, 2, 4] |
|
[1, 3, 4] |
CHECK
Question: 14
Using the binary search algorithm, what is the maximum number of iterations needed to find an element in an array containing 256 elements?
|
128 |
|
256 |
|
4 |
|
8 |
|
16 |
CHECK
Question: 15
How many comparisons will the selection sort algorithm make on an array of 8 elements?
|
3 |
|
8 |
|
24 |
|
28 |
|
64 |
CHECK
Question: 16
The following method counts the number of times even numbers appear in an ArrayList:
public int countEvenNumbers(ArrayList<Integer> numbers)
{
int count = 0;
// Missing code here
return count;
}
What should replace the comment // Missing code here?
|
for (int i = 0; i < numbers.size(); i++) { if (numbers.get(i) % 2 == 0) { count++; } } |
|
for (int i = 0; i <= numbers.size(); i++) { if (numbers.get(i) % 2 == 0) { count++; } } |
|
for (int i = 0; i < numbers.size(); i++) { if (numbers.get(i) % 2 == 1) { count++; } } |
|
for (int i = 0; i < numbers.size(); i++) { if (i % 2 == 0) { count++; } } |
|
for (int i = 0; i < numbers.size(); i++) { if (isEven(numbers.get(i))) { count++; } } |
CHECK
Question: 17
What is the precondition for binary search to work on an array?
|
The array must contain only integers. |
|
The array must be of even size. |
|
The array must be of odd size. |
|
The element being searched for must be in the array. |
|
The array must be sorted. |
CHECK
Question: 18
The following array is to be sorted biggest to smallest using insertion sort.
[10, 40, 50, 30, 20, 60]
What will the array look like after the third pass of the for loop?
|
[60, 50, 40, 30, 20, 10] |
|
[50, 40, 10, 30, 20, 60] |
|
[50, 40, 30, 10, 20, 60] |
|
[60, 50, 40, 30, 10, 20] |
|
[10, 30, 40, 50, 20, 60] |
CHECK
Question: 19
Which of the following algorithms take advantage of the divide and conquer paradigm?
|
Selection Sort and Insertion Sort |
|
Selection Sort and Merge Sort |
|
Sequential Search and Merge Sort |
|
Binary Search and Merge Sort |
|
Binary Search and Insertion Sort |
CHECK
Question: 20
The following method calculates the sum of the integers between a and b, inclusive.
public int sumNumbers(int a, int b) {
int sum = 0;
// Missing code here
return sum;
}
What should be the missing code?
|
while (a <= b) { sum += a; a++; } |
|
while (a <= b) { sum += b; a++; } |
|
while (a <= b) { a += sum; a++; } |
|
while (a <= b) { sum += a; b++; } |
|
while (a < b) { sum += a; a++; } |
CHECK
Question: 21
Of the sorting algorithms we’ve learned (selection sort, insertion sort, and merge sort), is merge sort the fastest in every case? Why?
|
Yes, because merge sort uses divide and conquer. |
|
Yes, because merge sort doesn’t look at every element in the array. |
|
No, because insertion sort is faster when the array has 1 or 2 elements. |
|
No, because selection sort is faster when the array is sorted. |
|
No, because insertion sort is faster when the array is sorted. |
CHECK
Question: 22
The following method is an implementation of sequential search:
public int sequentialSearch(int[] array, int key)
{
int i = 0;
int n = array.length;
while (/* missing conditional statement */)
{
i++;
}
if (i == n) return -1; // value not found
else return i; // value found at index i
}
What code should replace the /* missing conditional statement */ in order to have a functional sequential search?
|
key != array[i] |
|
i < n && key == array[i] |
|
key != array[i] && i < n |
|
i < n && key != array[i] |
|
i < n || key != array[i] |
CHECK
Question: 23
What is the decimal value of the binary number 1011?
|
3 |
|
9 |
|
11 |
|
13 |
|
24 |
CHECK
Question: 24
Assume A, B and C are booleans. Which of the following expressions are equivalent?
I. (!A || !B) II. (!A && !B) III. !(A && B)
|
I and II. |
|
I and III |
|
II and III |
|
I, II, and III |
|
None is equivalent with another. |
CHECK
Question: 25
Which of the following expressions evaluates to true? Assume A = true, B = false and C = false.
|
(A || B) && C |
|
(A && C) || B |
|
(A || C) || B |
|
!(A && B || !C) |
|
(!A || C || B) |
CHECK
Question: 26
Which of the following, as the /* body */ of the half, will return the double 3.5 when half(7) is called?
public double half(int x)
{
/* body */
}
|
return x/2; |
|
return (double)(x/2); |
|
return (double)x/2; |
|
return x//2; |
|
return double(x/2); |
CHECK
Question: 27
What is returned as a result of calling mystery(5)?
public int mystery(int b)
{
if (b == 0)
{
return 0;
}
if (b % 2 == 0)
{
return mystery(b - 1) + 2;
}
else
{
return mystery(b - 1) + 1;
}
}
|
5 |
|
7 |
|
12 |
|
0 |
|
This program creates an infinite loop. |
CHECK
Question: 28
Consider the following method foo. Assume n will always be greater than or equal to 1:
public int foo(int n)
{
if (n == 1 || n == 2)
{
return 2 * n;
}
else
{
return foo(n - 1) - foo(n - 2);
}
}
When foo(6) is executed, how many calls to foo will be made, including the original call?
|
7 |
|
9 |
|
13 |
|
15 |
|
25 |
CHECK
Question: 29
What will the following method print to the console?
public void foo()
{
int a = 0;
a++;
if (0 == 1 && a == 1)
{
System.out.println("foo");
}
else if (0 == 1 && (a + 1) == 2)
{
System.out.println("bar");
}
else
{
System.out.println("baz");
}
System.out.print(a);
}
|
baz 0 |
|
baz 1 |
|
baz 2 |
|
bar baz 1 |
|
bar baz 2 |
CHECK
Question: 30
You have an array of size 7, declared with the following code:
int[] arr = {1, 2, 3, 4, 5, 6, 7};
What do you get when you execute the following code?
System.out.println(arr[7]);
|
7 |
|
1 |
|
The code will execute, but nothing will be printed. |
|
A run-time error |
|
A compile-time error |
CHECK
Question: 31
You’re writing a program that will simulate a waiting line in a doctor’s office. When the user runs the program, she will be able to input either a patient’s name to add them to the waiting line or a number to see who is at that position in the waiting line. What would be the best way to store the waiting line in your program?
|
An ArrayList |
|
An array |
|
A string |
|
You can use an array or an ArrayList. |
|
None of the above. |
CHECK
Question: 32
Which of the following statements will compile with no errors?
- I ArrayList<int> arr = new List<int>();
- II ArrayList<Integer> arr = new List<Integer>();
- III ArrayList<Integer> arr = new ArrayList<Integer>();
- IV ArrayList<int> arr = new ArrayList<int>();
- V List<Integer> arr = new ArrayList<Integer>();
|
I, IV |
|
II, III, V |
|
II, III |
|
III, V |
|
III, IV |
CHECK
Question: 33
The following method
public String removeFromString(String old, String frag)
removes all occurences of the string frag from the string old. For example,
removeFromString("hello there!", "he") returns "llo tre!"
removeFromString("lalalala", "l") returns "aaaa"
Which of the following blocks of code will successfully implement removeFromString()?
|
private String removeFromString(String old, String frag) { int index = old.indexOf(frag); for (int i = 0; i < old.length(); i++) { if (index > -1) { String rest = old.substring(index + frag.length()); old = old.substring(0, index); index = old.indexOf(frag); } } return old; } |
|
private String removeFromString(String old, String frag) { int i = old.indexOf(frag); while (i > -1) { String rest = old.substring(i + frag.length()); old = old.substring(0, i); old = old + rest; i = old.indexOf(frag); } return old; } |
|
private String removeFromString(String old, String frag) { int i = old.indexOf(frag); while (i > -1) { String rest = old.substring(i + frag.length()); old = old.substring(0, i+1); old = old + rest; i = old.indexOf(frag); } return old; } |
|
private String removeFromString(String old, String frag) { int index = old.indexOf(frag); for (int i = 0; i < old.length(); i++) { if (index > -1) { String rest = old.substring(index + frag.length()); old = old.substring(0, index + 1); index = old.indexOf(frag); } } return old; } |
|
private String removeFromString(String old, String frag) { int index = old.indexOf(frag); for (int i = 0; i < old.length(); i++) { if (index > -1) { String rest = old.substring(index + 1 + frag.length()); old = old.substring(0, index + 1); index = old.indexOf(frag); } } return old; } |
CHECK
Question: 34
Your friend has sent you a secret message in the form of 2-D string arrays, but in order to decode it, you’ll have to find the difference between the two arrays. The secret message is the concatenation of all elements in arrA that are different than the corresponding elements in arrB. Given that the two arrays are of the same size, you write the following code:
public static String compareArrays(String[][] arrA, String[][] arrB) {
int rows = arrA.length;
int cols = arrA[0].length;
String secretMsg = "";
for (int i = 0; i < rows; i++)
{
/* EXPRESSION 1 */
secretMsg = secretMsg + arrA[i][j];
}
}
}
return secretMsg;
}
Which block of code can replace the /* EXPRESSION 1 */ comment to successfully decode the message?
· I
for (int j = 0; j < cols; j++)
{
if (!arrA[i][j].equals(arrB[i][j]))
{
· II
for (int j = 0; j < cols; j++)
{
if (arrA[i][j].compareTo(arrB[j][i]) != 0)
{
· III
for (int j = 0; j < cols; j++)
{
if (arrA[i][j].compareTo(arrB[i][j]) != 0)
{
· IV
for (int j = 0; j < cols; j++)
{
if (!arrA[i][j].equals(arrB[j][i]))
{
|
Only III |
|
Only IV |
|
Both I and III |
|
Both II and IV |
|
None of the above |
CHECK
Question: 35
Which of the following string initializations will result in an error?
|
String myString = "I'm not sure"; |
|
String myString = " ' ' ' "; |
|
String myString = "\"Hello World\""; |
|
String myString = "Hello "World""; |
|
String myString = " ' \\ ' "; |
CHECK
Question: 36
Which code snipped correctly imports the java ArrayList?
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import java.util.; |
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from java.util import ArrayList; |
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ArrayList = require('ArrayList'); |
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#include<java.util.ArrayList.h> |
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import java.util.ArrayList; |
CHECK
Question: 37
Given the following code snipped:
public class Person
{
String name;
public Person(String name)
{
this.name = name;
}
public static boolean sameName(Person otherPerson)
{
return this.name.equals(otherPerson.name);
}
}
What is the bug in the code?
|
Strings in java do not have a .equals method. |
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The this keyword should be replaced with the self keyword. |
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Static methods do not have access to the this keyword. |
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The Person class needs to have a default constructor. |
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The sameName method needs to be private. |
CHECK
Question: 38
What is wrong with the following interface declaration?
public interface Ball
{
private int airLevel;
public Ball()
{
airLevel = 0;
}
public void bounce();
public void roll();
public void inflate();
public void deflate();
}
|
airLevel = 0; needs to use the this keyword. Like so, this.airLevel = 0;. |
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Java interfaces must not include any implementation logic. |
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All of the method declarations should be private. |
|
All of the methods must include their implementation logic. |
|
Interface methods can not return void. |
CHECK
Question: 39
What does the following code segment do?
boolean myBoolean = false;
for (int i = 0; i < myArray.length; i++)
{
myBoolean = myBoolean && (myArray[i] > 0);
}
|
Always sets the value of myBoolean to false. |
|
Sets the value of myBoolean to true only if the last value in myArray is < 0. |
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Sets the value of myBoolean to true only if every value in myArrayis > 0. |
|
Sets the value of myBoolean to true if any value in myArray is > 0. |
|
Always sets the value of myBoolean to true. |
CHECK
Question: 40
Which of the following are true about a class that contains an abstract method?
· I. The class must not have fields declared.
· II. The class must be declared with the abstract keyword.
· III. The class can not have constructors.
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I and III only |
|
I and II only |
|
I, II and III |
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I only |
|
II only |
CHECK
Evaluate the mathematical expression: 6 + 12 ÷ 3 × (5 – 6)
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-6 |
|
-4 |
|
2 |
|
6 |
CHECK
Question: 2
If x represents the area of the number line colored orange, which inequality accurately reflects the value of x?
|
x < 4 |
|
x > 4 |
|
x ≥ 4 |
|
x ≤ 4 |
CHECK
Question: 3
Christine will go to the beach if it’s not raining and if it’s between 75°F and 95°F. Otherwise, she’ll go to the movies. In which of the following cases will Christine go to the beach?
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It’s 80°F and raining |
|
It’s not raining and 73°F |
|
It’s raining and 96°F |
|
It’s not raining and 83°F |
CHECK
Question: 4
Karel the Dog is instructed to move forward three spaces. Then, if Karel is standing on a ball, Karel will turn left and move forward one space. Otherwise, Karel will turn right and move forward one space. Given the starting point below, where will Karel end up? Starting Point:
|
|
|
|
|
|
|
|
CHECK
Question: 5
Consider the following output.
1 1 1 1 1
2 2 2 2
3 3 3
4 4
5
Which of the following code segments will produce this output?
|
for (int j = 1; j <= 5; j++) { for (int k = 1; k <= 5; k++) { System.out.print(j + " "); } System.out.println(); } |
|
for (int j = 1; j <= 5; j++) { for (int k = 1; k <= j; k++) { System.out.print(j + " "); } System.out.println(); } |
|
for (int j = 1; j <= 5; j++) { for (int k = 5; k >= 1; k--) { System.out.print(j + " "); } System.out.println(); } |
|
for (int j = 1; j <= 5; j++) { for (int k = 5; k >= j; k--) { System.out.print(j + " "); } System.out.println(); } |
CHECK
Question: 6
Which of the following successfully switches the integer values of the variables x and y? temp may be used as a temporary variable if necessary.
|
x = y; y = x; |
|
int temp = x; y = x; temp = y; |
|
x = y; y = temp; |
|
int temp = x; x = y; y = temp; |
CHECK
Question: 7
A car dealership is writing a program to store information about the cars for sale. You create a class called Car to represent a single car that is for sale.
Which of these would not make sense as an instance variable in the Car class
|
private double milesPerGallon |
|
private boolean hasAirConditioning |
|
private int numDoors |
|
private int totalNumCars |
CHECK
Question: 8
How many times will the loop execute?
int i = 0;
while(i < 50)
{
System.out.println(i);
i += 10;
}
|
0 |
|
5 |
|
50 |
|
4 |
CHECK
Question: 9
What is a method?
|
A procedure that is defined by the user. |
|
A keyword used to loop for a fixed amount of time. |
|
A place where we can store data. |
|
The type that is given to a variable. |
CHECK
Question: 10
What does this method call output?
public double doubleOrNothing(double myDouble)
{
return (double) (int) myDouble * 2;
}
doubleOrNothing(9.9);
|
This method is improperly written. |
|
18.0 |
|
18.8 |
|
20 |
CHECK
Question: 11
Given this code snippet,
public class GoldenRetriever
{
public GoldenRetriever(String name)
{
this.name = name;
}
}
what is missing from the class definition?
|
Need to declare the name instance variable |
|
Missing void in constructor definition |
|
Class constructors must be private |
|
Java does not use the keyword this, instead it uses self |
|
No constructor is defined for the class |
CHECK
Question: 12
Given the definitions of class A and class B
class A
{
public int i;
public int j;
public A()
{
i = 1;
j = 2;
}
}
class B extends A
{
int a;
public B()
{
super();
}
}
what is the output of this code
B obj = new B();
System.out.println(obj.i + " " + obj.j);
|
Runtime error |
|
Compilation error |
|
1 2 |
|
2 1 |
CHECK
Question: 13
What is the output of the following program?
public class SayHello
{
public void run()
{
String stringArray[] = {"h", "e", "l", "l", "o", "w"};
for(int i=0; i <= stringArray.length; i++)
{
System.out.print(stringArray[i]);
}
}
}
|
hel |
|
hellow |
|
Error |
|
hello |
|
None of the above |
CHECK
Question: 14
Which is the correct way to construct and assign a 2D array, with 12 rows and 17 columns, to the variable pizza?
|
int[12][17] pizza; |
|
int[12][17] pizza = new int[12][17]; |
|
int[][] pizza = new int[12][17]; |
|
int[12][17] pizza = new int[][]; |
|
int[][] pizza = new int[][](12, 17); |
CHECK
Question: 15
Given this array:
1 2 4 5 6 7 8 12 14 21 22 39 53
How many comparisons are required to find 39 using the Binary Search?
|
2 |
|
3 |
|
5 |
|
10 |
CHECK