Question 1

Which one of the following code snippets accepts the integer input in an array list named num1 and stores the even integers of num1 in another array list named evennum?

Accepted Answer

The code snippet in choice A correctly checks if the number is even and adds it to the evennum list.

Question 2

Consider the following code snippet: public static void check(ArrayList<Integer> chknum1)
{
Int cnt = 0;
For(int i = 0; i < chknum1.size(); i++)
{
If(chknum1.get(i) == 0)
{
Cnt++;
}
}
System.out.println("The total 0 values in the list are: " + cnt);
}
Which one of the following is true about the check method in the given code snippet?

Accepted Answer

The check method counts all the elements with value 0 in an array list passed as a parameter to the method.

Question 3

Consider the following code snippet: ArrayList arrList = new ArrayList(); For (int i = 0; i < arrList.size(); i++) { ArrList.add(i + 3); } What value is stored in the element of the array list at index 0?

Accepted Answer

The loop condition `i < arrList.size()` is never true initially because `arrList` is empty, so the loop body never executes, and no elements are added to the list.

Question 4

Which one of the following statements about declaring an array list as a method parameter is true?

Accepted Answer

An array list declared as a method parameter is not a constant value by default and can be modified inside the method. Therefore, option A is incorrect. There is no need to specify the size of the array list while declaring it as a method parameter, so option B is also incorrect. As array lists are passed as reference types in Java, any changes made to the array list inside the method will be reflected outside the method as well. Hence, option C is also incorrect. Option D correctly states that an array list value can be modified inside the method if it is declared as a parameter.

Question 5

What is the result of the following definition of an array list? ArrayList<Double> points;

Accepted Answer

The statement defines an ArrayList reference of type Double, but does not create an ArrayList object. The size of the ArrayList will be determined when an object is actually created using the "new" keyword.

Question 6

Your program needs to store an integer sequence of unknown length. Which of the following is most suitable to use?

Accepted Answer

Since the length of the integer sequence is unknown, it would be better to use the dynamic size of an ArrayList instead of a fixed-size array.

Question 7

Which one of the following is a correct declaration for a method named passAList that has as arguments an array list myList of size 10 and an integer array intArr of size 20, and that modifies the contents of myList and intArr?

Accepted Answer

In Java, you declare a method with parameters by specifying the type and name of each parameter. The size of the array or list is not part of the method signature. Therefore, the correct declaration is with the types ArrayList<Integer> and int[] without specifying sizes.

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

The code accesses the elements arr[0][2] (which is 3) and arr[1][2] (which is 6) and adds them together, resulting in 9.

Question 9

Consider the following code snippet: ArrayList num1 = new ArrayList(); Int data; Scanner in = new Scanner(System.in); For (int i = 0; i < 5; i++) { Data = in.nextInt(); Num1.add(data); If (data == 0 && num1.size() > 3) { Num1.remove(num1.size() - 1); } } System.out.println("size is : " + num1.size()); What is the output of the given code snippet if the user enters 1,2,0,0,1 as the input?

Accepted Answer

The code adds each input to the ArrayList. When a 0 is entered and the list size is greater than 3, it removes the last element. After inputs 1, 2, 0, 0, 1, the list size is 4.

Question 10

What is the value of the cnt variable after the execution of the code snippet below? ArrayList somenum = new ArrayList(); Somenum.add(1); Somenum.add(2); Somenum.add(1); Int cnt = 0; For (int index = 0; index < somenum.size(); index++) { If (somenum.get(index) % 2 == 0) { Cnt++; } }

Accepted Answer

The answer of What is the value of the cnt...

Question 11

Consider the following line of code for calling a method named func1: func1(listData, varData);
Which one of the following method headers is valid for func1, where listData is an integer array list and varData is an integer variable?

Accepted Answer

The method header C correctly matches the types and order of the arguments: an ArrayList of Integers and an integer variable.

Question 12

What is the output of the following code snippet? ArrayList<Integer> num;
Num)add(4);
System.out.println(num.size());

Accepted Answer

The code will result in an error because the ArrayList 'num' is declared but not initialized before attempting to add an element to it.

Question 13

Consider the following code snippet: ArrayList somedata = new ArrayList(); Somedata.add(10.5); What is the size of the array list somedata after the given code snippet is executed?

Accepted Answer

The code snippet creates an ArrayList of Double objects and adds one element to it. The size of the ArrayList after the code snippet is executed is 1.

Question 14

What is the value of myArray[1][2] after this code snippet is executed?
Int count = 0;
Int[][] myArray = new int[4][5];
For (int i = 0; i < 5; i++)
{
For (int j = 0; j < 4; j++)
{
MyArray[j][i] = count;
Count++;
}
}

Accepted Answer

The answer of What is the value of myArray[1][2] after...

Question 15

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

Accepted Answer

To calculate the largest value in an array list, it's essential to ensure that the array list contains at least one element. Without any elements, it's impossible to determine a largest value, making this check crucial. The number of elements beyond one, or the specific values in any positions (including the first), are not necessary conditions for the process of finding the largest value.

Question 16

Which one of the following is a valid signature of a method with an integer two-dimensional array parameter of size 10 x 10?

Accepted Answer

In Java, the size of an array is not part of its type, so you declare a two-dimensional array parameter as `int[][] arr`. The size (10x10) is not specified in the method signature.

Question 17

Which one of the following is the correct code snippet for calculating the largest value in an integer array list arrList of size 10?

Accepted Answer

The correct approach is to initialize the maximum with the first element of the list and then iterate through the list starting from the second element to find the largest value.

Question 18

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

Option A is incorrect because the size of an ArrayList is not specified when declaring the method parameter.
Option B is incorrect because the comma after the ArrayList parameter is not valid syntax.
Option D is incorrect because the parameter name alone does not specify the data type or size of the parameter. 
Therefore, the correct option is C, where the method is declared with the ArrayList parameter without specifying the size.

Question 19

Consider the following code snippet:
Int val = arr[0][2];
Which value of arr is stored in the val variable?

Accepted Answer

In programming, array indices start from 0. Therefore, arr[0][2] refers to the first row and the third column.

Question 20

What is the output of the following code snippet? public static int check(ArrayList listData) { Int sum = 0; For (int i = 0; i < listData.size(); i++) { Sum = sum + listData.get(i); } Return sum; } Public static void main(String[] args) { ArrayList vdata = new ArrayList(); Int rsum; For (int cnt = 0; cnt < 3; cnt++) { Vdata.add(cnt + 1); } Rsum = check(vdata); System.out.println(rsum); }

Accepted Answer

The code adds numbers 1, 2, and 3 to the ArrayList, and the sum of these numbers is 6.

Quiz 7: Arrays and Array Lists

Which one of the following code snippets accepts the integer input in an array list named num1 and stores the even integers of num1 in another array list named evennum?

Consider the following code snippet: ArrayList<Integer> arrList = new ArrayList<Integer>() ; For (int i = 0; i < arrList.size() ; i++) { ArrList.add(i + 3) ; } What value is stored in the element of the array list at index 0?

Which one of the following statements about declaring an array list as a method parameter is true?

What is the result of the following definition of an array list? ArrayList<Double> points;

Your program needs to store an integer sequence of unknown length. Which of the following is most suitable to use?

Which one of the following is a correct declaration for a method named passAList that has as arguments an array list myList of size 10 and an integer array intArr of size 20, and that modifies the contents of myList and intArr?

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?

Consider the following line of code for calling a method named func1: func1(listData, varData) ; Which one of the following method headers is valid for func1, where listData is an integer array list and varData is an integer variable?

What is the output of the following code snippet? ArrayList<Integer> num; Num) add(4) ; System.out.println(num.size() ) ;

Consider the following code snippet: ArrayList<Double> somedata = new ArrayList<Double>() ; Somedata.add(10.5) ; What is the size of the array list somedata after the given code snippet is executed?

What is the value of myArray[1][2] after this code snippet is executed? Int count = 0; Int[][] myArray = new int[4][5]; For (int i = 0; i < 5; i++) { For (int j = 0; j < 4; j++) { MyArray[j][i] = count; Count++; } }

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

Which one of the following is a valid signature of a method with an integer two-dimensional array parameter of size 10 x 10?

Which one of the following is the correct code snippet for calculating the largest value in an integer array list arrList of size 10?

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?

Consider the following code snippet: Int val = arr[0][2]; Which value of arr is stored in the val variable?