Question 1

When a Java program terminates and reports an exception, the error message contains which pieces of useful information?
I. The compile and revision control history of the source code changes that caused the error
II. The name of the exception that occurred
III. The stack trace

Accepted Answer

A)  I, II 
B)  I, III 
C)  II, III 
D)  I, II, III

Question 2

What is the output of the code snippet below?
Int[][] arr =
{
{ 1, 2, 3, 0 },
{ 4, 5, 6, 0 },
{ 0, 0, 0, 0 }
};
Int val = arr[1][2] + arr[1][3];
System.out.println(val);

Accepted Answer

A)  5 
B)  6 
C)  7 
D)  9

Question 3

What is the result of executing this code snippet?
Int[] marks = { 90, 45, 67 };
For (int i = 0; i <= 3; i++)
{
System.out.println(marks[i]);
}

Accepted Answer

A)  The code snippet does not give any output. 
B)  The code snippet displays all the marks stored in the array without any redundancy. 
C)  The code snippet causes a bounds error. 
D)  The code snippet executes an infinite loop.

Question 4

Which one of the following is the correct header for a method named arrMeth that is called like this: arrMeth(intArray); // intArray is an integer array of size 3

Accepted Answer

A)  public static void arrMeth(int[] ar, int n) 
B)  public static void arrMeth(r[], n) 
C)  public static void arrMeth(int n , int[] ar) 
D)  public static void arrMeth(int[] ar)

Question 5

What will be printed by the statements below?
Int[] values = { 4, 5, 6, 7};
Values[0] = values[3];
Values[3] = values[0];
For (int i = 0; i < values.length; i++)
System.out.print (values[i] + " ");

Accepted Answer

A) 7 5 6 4 
B) 7 6 5 4 
C) 7 5 6 7 
D) 4 5 6 4

Question 6

Complete the following code snippet with the correct enhanced for loop so it iterates over the array without using an index variable. String[] arr = { "abc", "def", "ghi", "jkl" };
___________________
{
System.out.print(str);
}

Accepted Answer

A)  for (String str : arr) 
B)  for (str : String arr) 
C)  for (str[] : arr) 
D)  for (arr[] : str)

Question 7

What is the output of the following code?
Int[][] counts =
{
{ 0, 0, 1 },
{ 0, 1, 1, 2 },
{ 0, 0, 1, 4, 5 },
{ 0, 2 }
};
System.out.println(counts[3].length);

Accepted Answer

A)  2 
B)  3 
C)  4 
D)  5

Question 8

Consider the following code snippet:
Int[][] arr =
{
{ 1, 2, 3 },
{ 4, 5, 6 }
};
Int val = arr[0][2] + arr[1][2];
System.out.println(val);
What is the output of the given code snippet on execution?

Accepted Answer

A)  5 
B)  7 
C)  9 
D)  10

Question 9

What will be printed by the statements below? ArrayList names = new ArrayList(); Names.add("Annie"); Names.add("Bob"); Names.add("Charles"); Names.set(2, "Doug"); Names.add(0, "Evelyn"); System.out.print (names);

Accepted Answer

A) [Annie, Bob, Charles, Doug, Evelyn] 
B) [Evelyn, Annie, Bob, Doug] 
C) [Evelyn, Doug, Charles] 
D) [Evelyn, Annie, Doug, Charles]

Question 10

What should you check for when calculating the largest value in an array list?

Accepted Answer

A)  The array list contains at least one element. 
B)  The array list contains at least two elements. 
C)  The array list contains the minimum value in the first element. 
D)  The array list contains the maximum value in the first element.

Question 11

Which one of the following is a correct declaration for a method named passAList with the array list num of size 5 as a parameter?

Accepted Answer

A) public static void passAList(ArrayList num[5]) B) public static void passAList(ArrayList num, 5) C) public static void passAList(ArrayList num) D) public static void passAList(num)

Question 12

When an array reading and storing input runs out of space

Accepted Answer

A)  the program could be recompiled with a bigger size for the array. 
B)  the array could be "grown" using the growArray method. 
C)  it automatically resizes to accommodate new elements. 
D)  the array could be "grown" using the new command and the copyOf method.

Question 13

When the order of the elements is unimportant, what is the most efficient way to remove an element from an array?

Accepted Answer

A)  Delete the element and move each element after that one to a lower index. 
B)  Replace the element to be deleted with the last element in the array. 
C)  Replace the element to be deleted with the first element in the array. 
D)  Replace the element with the next element.

Question 14

What will be printed by the statements below? ArrayList names = new ArrayList(); Names.add("Annie"); Names.add("Bob"); Names.add("Charles"); For (int i = 0; i < 3; i++) { String extra = names.get(i); Names.add (extra); } System.out.print (names);

Accepted Answer

A) [Annie, Bob, Charles, Annie, Bob, Charles] 
B) [Annie, Bob, Charles, Charles, Bob, Annie] 
C) [Annie, Annie, Bob, Bob, Charles, Charles] 
D) [Annie, Bob, Charles, Bob, Charles]

Question 15

Which code snippet finds the largest value in an array that is only partially full?

Accepted Answer

A)  double largest = values[0];
For (int i = 1; i  largest)
{
Largest = values[i];
}
} 
B)  double largest = values[0];
For (int i = 1; i  largest)
{
Largest = values[i];
}
} 
D)  double largest = values[0];
For (int i = 1; i < currSize; i++)
{
If (values[i] < largest)
{
Largest = values[i];
}
}

Question 16

What is the output of the following statements? ArrayList names = new ArrayList(); Names.add("Bob"); Names.add(0, "Ann"); Names.remove(1); Names.add("Cal"); Names.set(1, "Tony"); For (String s : names) { System.out.print(s + ", "); }

Accepted Answer

A)  Cal, Bob, Ann 
B)  Ann, Bob 
C)  Ann, Tony 
D)  Cal, Bob, Tony

Question 17

Consider the following code snippet: String[] data = { "123", "ghi", "jkl", "def", "%&*" };
Which statement sorts the data array in ascending order?

Accepted Answer

A)  data = Arrays.sort(); 
B)  Arrays.sort(data); 
C)  data = Arrays.sort(data.length); 
D)  data = Arrays.sort(data);

Question 18

What is displayed after executing the given code snippet?
Int[] mymarks = new int[10];
Int total = 0;
Scanner in = new Scanner(System.in);
For (int cnt = 1; cnt <= 10; cnt++)
{
System.out.print("Enter the marks: ");
Mymarks[cnt] = in.nextInt();
Total = total + mymarks[cnt];
}
System.out.println(total);

Accepted Answer

A)  The code snippet displays the total marks of all ten subjects. 
B)  The for loop causes a run-time time error on the first iteration. 
C)  The code snippet causes a bounds error. 
D)  The code snippet displays zero.

Question 19

How many elements can be stored in a two-dimensional 5 by 6 array?

Accepted Answer

A)  5 
B)  6 
C)  11 
D)  30

Question 20

It may be necessary to "grow" an array when reading inputs because

Accepted Answer

A)  the number of inputs may not be known in advance. 
B)  arrays in Java must be resized after every 100 elements. 
C)  arrays are based on powers of two. 
D)  the only alternative is a bounds exception.

Exam 7: Arrays and Array Lists

When a Java program terminates and reports an exception, the error message contains which pieces of useful information? I. The compile and revision control history of the source code changes that caused the error II. The name of the exception that occurred III. The stack trace

What is the output of the code snippet below? Int[][] arr = { { 1, 2, 3, 0 }, { 4, 5, 6, 0 }, { 0, 0, 0, 0 } }; Int val = arr[1][2] + arr[1][3]; System.out.println(val) ;

What is the result of executing this code snippet? Int[] marks = { 90, 45, 67 }; For (int i = 0; i <= 3; i++) { System.out.println(marks[i]) ; }

Which one of the following is the correct header for a method named arrMeth that is called like this: arrMeth(intArray) ; // intArray is an integer array of size 3

What will be printed by the statements below? Int[] values = { 4, 5, 6, 7}; Values[0] = values[3]; Values[3] = values[0]; For (int i = 0; i < values.length; i++) System.out.print (values[i] + " ") ;

Complete the following code snippet with the correct enhanced for loop so it iterates over the array without using an index variable. String[] arr = { "abc", "def", "ghi", "jkl" }; ___________________ { System.out.print(str) ; }

What is the output of the following code? Int[][] counts = { { 0, 0, 1 }, { 0, 1, 1, 2 }, { 0, 0, 1, 4, 5 }, { 0, 2 } }; System.out.println(counts[3].length) ;

Consider the following code snippet: Int[][] arr = { { 1, 2, 3 }, { 4, 5, 6 } }; Int val = arr[0][2] + arr[1][2]; System.out.println(val) ; What is the output of the given code snippet on execution?

What will be printed by the statements below? ArrayList<String> names = new ArrayList<String>() ; Names.add("Annie") ; Names.add("Bob") ; Names.add("Charles") ; Names.set(2, "Doug") ; Names.add(0, "Evelyn") ; System.out.print (names) ;