4. Now examine the ArrayList methods in the above table, a) Which method retrieves elements from the ArrayList? b) Which method replaces the value of an element that already exists in the ArrayList? c) Which two methods initializes the value of an element? d) How do the two methods in (c) differ? Which method(s) would be appropriate in the above Java program (after we convert it to work with ArrayLists)?
4. Now examine the ArrayList methods in the above table, a) Which method retrieves elements from the ArrayList? b) Which method replaces the value of an element that already exists in the ArrayList? c) Which two methods initializes the value of an element? d) How do the two methods in (c) differ? Which method(s) would be appropriate in the above Java program (after we convert it to work with ArrayLists)?
Computer Networking: A Top-Down Approach (7th Edition)
7th Edition
ISBN:9780133594140
Author:James Kurose, Keith Ross
Publisher:James Kurose, Keith Ross
Chapter1: Computer Networks And The Internet
Section: Chapter Questions
Problem R1RQ: What is the difference between a host and an end system? List several different types of end...
Related questions
Question
100%
4. Now examine the ArrayList methods in the above table,
a) Which method retrieves elements from the ArrayList?
b) Which method replaces the value of an element that already exists in the ArrayList?
c) Which two methods initializes the value of an element?
d) How do the two methods in (c) differ? Which method(s) would be appropriate in the above Java program (after we convert it to work with ArrayLists)?
![## Accessing and Modifying Array Elements in Java
Here is a quick review of how array elements are modified and accessed:
```java
public class BasicArray {
public static void main(String[] args) {
int[] basic = new int[4];
for (int i = 0; i < basic.length; i++) {
basic[i] = i + 1;
}
for (int i = 0; i < basic.length; i++) {
basic[i] = basic[i] * 5;
}
for (int i = 0; i < basic.length; i++) {
System.out.println(basic[i]);
}
}
}
```
### Explanation:
- **Lines 3-4:** An integer array `basic` of size 4 is declared.
- **Lines 5-6:** A for-loop initializes the array elements to `i + 1`. For example, the array will be populated as `[1, 2, 3, 4]`.
- **Lines 7-8:** Another for-loop modifies each element by multiplying it by 5. The array becomes `[5, 10, 15, 20]`.
- **Lines 10-12:** Finally, a for-loop prints each element of the array.
---
Because `ArrayList` is a Java class, we need `set` and `get` methods to modify the ArrayList. The `E` type refers to the base type of the `ArrayList`:
| Method (Parameters) | Return Value Type | Description |
|----------------------------|-------------------|-----------------------------------------------------------------------------|
| `add(E element)` | `boolean` | Appends the specified element to the end of this list. |
| `add(int index, E element)`| `void` | Inserts the specified element at the specified position in this list. |
| `get(int index)` | `E` | Returns the element at the specified position in this list. |
| `set(int index, E element)`| `E` | Replaces the element at the specified position in this list with the specified element. Returns the element previously at the specified position. |
| `size()` | `int` | Returns the number of elements in this list. |](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F6cf78908-a1f9-4330-9ece-f4021df10613%2Fcd099ace-86c8-43b3-89ca-e958e52d867c%2Fka3nscr_processed.png&w=3840&q=75)
Transcribed Image Text:## Accessing and Modifying Array Elements in Java
Here is a quick review of how array elements are modified and accessed:
```java
public class BasicArray {
public static void main(String[] args) {
int[] basic = new int[4];
for (int i = 0; i < basic.length; i++) {
basic[i] = i + 1;
}
for (int i = 0; i < basic.length; i++) {
basic[i] = basic[i] * 5;
}
for (int i = 0; i < basic.length; i++) {
System.out.println(basic[i]);
}
}
}
```
### Explanation:
- **Lines 3-4:** An integer array `basic` of size 4 is declared.
- **Lines 5-6:** A for-loop initializes the array elements to `i + 1`. For example, the array will be populated as `[1, 2, 3, 4]`.
- **Lines 7-8:** Another for-loop modifies each element by multiplying it by 5. The array becomes `[5, 10, 15, 20]`.
- **Lines 10-12:** Finally, a for-loop prints each element of the array.
---
Because `ArrayList` is a Java class, we need `set` and `get` methods to modify the ArrayList. The `E` type refers to the base type of the `ArrayList`:
| Method (Parameters) | Return Value Type | Description |
|----------------------------|-------------------|-----------------------------------------------------------------------------|
| `add(E element)` | `boolean` | Appends the specified element to the end of this list. |
| `add(int index, E element)`| `void` | Inserts the specified element at the specified position in this list. |
| `get(int index)` | `E` | Returns the element at the specified position in this list. |
| `set(int index, E element)`| `E` | Replaces the element at the specified position in this list with the specified element. Returns the element previously at the specified position. |
| `size()` | `int` | Returns the number of elements in this list. |
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
Recommended textbooks for you
Computer Networking: A Top-Down Approach (7th Edi…
Computer Engineering
ISBN:
9780133594140
Author:
James Kurose, Keith Ross
Publisher:
PEARSON
Computer Organization and Design MIPS Edition, Fi…
Computer Engineering
ISBN:
9780124077263
Author:
David A. Patterson, John L. Hennessy
Publisher:
Elsevier Science
Network+ Guide to Networks (MindTap Course List)
Computer Engineering
ISBN:
9781337569330
Author:
Jill West, Tamara Dean, Jean Andrews
Publisher:
Cengage Learning
Computer Networking: A Top-Down Approach (7th Edi…
Computer Engineering
ISBN:
9780133594140
Author:
James Kurose, Keith Ross
Publisher:
PEARSON
Computer Organization and Design MIPS Edition, Fi…
Computer Engineering
ISBN:
9780124077263
Author:
David A. Patterson, John L. Hennessy
Publisher:
Elsevier Science
Network+ Guide to Networks (MindTap Course List)
Computer Engineering
ISBN:
9781337569330
Author:
Jill West, Tamara Dean, Jean Andrews
Publisher:
Cengage Learning
Concepts of Database Management
Computer Engineering
ISBN:
9781337093422
Author:
Joy L. Starks, Philip J. Pratt, Mary Z. Last
Publisher:
Cengage Learning
Prelude to Programming
Computer Engineering
ISBN:
9780133750423
Author:
VENIT, Stewart
Publisher:
Pearson Education
Sc Business Data Communications and Networking, T…
Computer Engineering
ISBN:
9781119368830
Author:
FITZGERALD
Publisher:
WILEY