All Flashcards
What is the definition of Array?
A container object that holds a fixed number of values of a single type.
What is the definition of Index?
The position of an element within an array, starting from 0.
What is the definition of Traversing an array?
The process of visiting each element in an array and performing some operation on it.
What is the definition of ArrayIndexOutOfBoundsException?
An exception thrown when trying to access an array element with an invalid index (e.g., negative or beyond the array's length).
What is the definition of Enhanced For Loop?
A simplified for loop for iterating over elements in an array without needing to manage indices directly.
What is the definition of Zero-based indexing?
A system where the first element of an array has an index of 0, the second has an index of 1, and so on.
What is the definition of NullPointerException?
An exception thrown when attempting to use a reference that points to null (no object).
What is the definition of Data Structure?
A way of organizing and storing data in a computer so that it can be used efficiently.
What is the definition of Primitive Data Type?
Basic data types such as int, boolean, and double that are built into a programming language.
What is the definition of Reference Data Type?
Data types that store the memory address of an object, such as String and arrays.
What is array initialization?
Assigning an initial size and optionally values to the elements of an array when it is created.
What is the significance of array indices?
Array indices provide a way to access and manipulate individual elements within the array.
What is array traversal?
Iterating through each element of the array to perform an operation.
Why is it important to avoid ArrayIndexOutOfBoundsException?
Accessing an invalid index can lead to program crashes or unexpected behavior.
How does the enhanced for loop simplify array processing?
It provides a concise way to iterate through array elements without managing indices, but it can't modify the array.
What happens if an array is created but not explicitly populated with values?
The elements of the array will be initialized with the default values for their type (e.g., 0 for int, false for boolean, null for objects).
Why are arrays fixed in size?
Arrays are fixed in size to ensure memory allocation is contiguous and efficient, which allows for fast access to elements.
What is the purpose of using loops with arrays?
Loops allow for efficient processing of each element in an array, such as modifying values, searching for specific elements, or performing calculations.
What are some common array algorithms?
Finding min/max values, computing sums/averages, determining if elements meet certain criteria, shifting/rotating elements, and reversing order.
What are the limitations of enhanced for loops?
They cannot be used to modify the original array, and they do not provide access to the index of the elements.
What does the following code output?
java
int[] numbers = new int[3];
System.out.println(numbers[0]);
0
What does the following code output?
java
int[] values = {5, 10, 15};
System.out.println(values[1]);
10
What does the following code output?
java
int[] nums = {1, 2, 3, 4, 5};
int sum = 0;
for (int num : nums) {
sum += num;
}
System.out.println(sum);
15
Identify the error in the following code:
java
int[] arr = new int[5];
arr[5] = 10;
ArrayIndexOutOfBoundsException. The valid indices are 0 to 4.
What does the following code output?
java
int[] arr = {5, 4, 3, 2, 1};
for (int i = 0; i < arr.length; i++) {
arr[i] = arr[i] * 2;
}
System.out.println(arr[2]);
6
What does the following code output?
java
String[] names = new String[2];
System.out.println(names[0]);
null
Identify the error in the following code:
java
int[] numbers = {1, 2, 3};
for (int i = 1; i <= numbers.length; i++) {
System.out.println(numbers[i]);
}
ArrayIndexOutOfBoundsException. The loop should iterate from 0 to numbers.length - 1.
What does the following code output?
java
int[] values = {10, 20, 30, 40, 50};
int count = 0;
for (int value : values) {
if (value > 25) {
count++;
}
}
System.out.println(count);
3
What does the following code output?
java
int[] numbers = {5, 2, 8, 1, 9};
int max = numbers[0];
for (int number : numbers) {
if (number > max) {
max = number;
}
}
System.out.println(max);
9
What does the following code output?
java
int[] arr = {1, 2, 3, 4, 5};
int[] newArr = new int[arr.length];
for (int i = 0; i < arr.length; i++) {
newArr[i] = arr[arr.length - 1 - i];
}
System.out.println(newArr[0]);
5