Complete this method for removing and returning the first element of a linked list. If the list is empty, return null. Lists.java 1 import java.util. Iterator; 2 import java.util.LinkedList; 3 4 public class Lists 5 { 6 7 8 9 10 11 12 } 13} Lists Tester.java 1 import java.util.LinkedList; 2 import java.util.Arrays; 3 7 8 4 public class Lists Tester 5 { 6 9 public static String removeFirst (LinkedList strings) { · 10 11 12 13 " 14 15 16 17 Iterator iter = strings. iterator(); String result = null; return result; 18 19 20 21 22 23 } public static void main(String[] args) { } LinkedList lst1 = new LinkedListo(Arrays.asList("Peter", "Paul", "Mary")); String resl Lists.removeFirst (lst1); System.out.println(res1); System.out.println("Expected: Peter"); System.out.println(lst1); System.out.println("Expected: [Paul, Mary]"); LinkedList 1st2 = new Linked List (Arrays.asList("A", "B", "C", "D", "E")); String res2 Lists.removeFirst (1st2); System.out.println(res2); System.out.println("Expected: A"); System.out.println(1st2); System.out.println("Expected: [B, C, D, E]");
Complete this method for removing and returning the first element of a linked list. If the list is empty, return null. Lists.java 1 import java.util. Iterator; 2 import java.util.LinkedList; 3 4 public class Lists 5 { 6 7 8 9 10 11 12 } 13} Lists Tester.java 1 import java.util.LinkedList; 2 import java.util.Arrays; 3 7 8 4 public class Lists Tester 5 { 6 9 public static String removeFirst (LinkedList strings) { · 10 11 12 13 " 14 15 16 17 Iterator iter = strings. iterator(); String result = null; return result; 18 19 20 21 22 23 } public static void main(String[] args) { } LinkedList lst1 = new LinkedListo(Arrays.asList("Peter", "Paul", "Mary")); String resl Lists.removeFirst (lst1); System.out.println(res1); System.out.println("Expected: Peter"); System.out.println(lst1); System.out.println("Expected: [Paul, Mary]"); LinkedList 1st2 = new Linked List (Arrays.asList("A", "B", "C", "D", "E")); String res2 Lists.removeFirst (1st2); System.out.println(res2); System.out.println("Expected: A"); System.out.println(1st2); System.out.println("Expected: [B, C, D, E]");
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![**Educational Content: Removing the First Element from a Linked List in Java**
In this exercise, we will explore how to remove and return the first element of a linked list using Java. If the list is empty, the method should return `null`.
The implementation involves two primary Java files: `Lists.java` and `ListsTester.java`.
### `Lists.java`
This file defines a `Lists` class with a static method `removeFirst`:
```java
import java.util.Iterator;
import java.util.LinkedList;
public class Lists
{
public static String removeFirst(LinkedList<String> strings)
{
Iterator<String> iter = strings.iterator();
String result = null;
// Implementation Details
return result;
}
}
```
**Key Points:**
- The `removeFirst` method accepts a `LinkedList` of strings.
- It initializes an iterator for the list.
- The method is designed to return the first element, or `null` if the list is empty.
### `ListsTester.java`
This file contains the `ListsTester` class with the `main` method to test our `removeFirst` method:
```java
import java.util.LinkedList;
import java.util.Arrays;
public class ListsTester
{
public static void main(String[] args)
{
LinkedList<String> lst1 = new LinkedList<>(Arrays.asList("Peter", "Paul", "Mary"));
String res1 = Lists.removeFirst(lst1);
System.out.println(res1);
System.out.println("Expected: Peter");
System.out.println(lst1);
System.out.println("Expected: [Paul, Mary]");
LinkedList<String> lst2 = new LinkedList<>(Arrays.asList("A", "B", "C", "D", "E"));
String res2 = Lists.removeFirst(lst2);
System.out.println(res2);
System.out.println("Expected: A");
System.out.println(lst2);
System.out.println("Expected: [B, C, D, E]");
}
}
```
**Test Description:**
- **Test 1:** A linked list `lst1` with elements "Peter", "Paul", and "Mary" is created.
- The first element "Peter" is expected to be removed and printed.
- The modified list should contain "Paul" and "Mary".
- **Test 2:** A linked list `lst2` with elements](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F1580620b-ec3d-48da-8d5f-e0e1d6dd1757%2F06e1eb18-a197-46cd-9c0d-eac65be1b87f%2Fp16ay6f_processed.png&w=3840&q=75)
Transcribed Image Text:**Educational Content: Removing the First Element from a Linked List in Java**
In this exercise, we will explore how to remove and return the first element of a linked list using Java. If the list is empty, the method should return `null`.
The implementation involves two primary Java files: `Lists.java` and `ListsTester.java`.
### `Lists.java`
This file defines a `Lists` class with a static method `removeFirst`:
```java
import java.util.Iterator;
import java.util.LinkedList;
public class Lists
{
public static String removeFirst(LinkedList<String> strings)
{
Iterator<String> iter = strings.iterator();
String result = null;
// Implementation Details
return result;
}
}
```
**Key Points:**
- The `removeFirst` method accepts a `LinkedList` of strings.
- It initializes an iterator for the list.
- The method is designed to return the first element, or `null` if the list is empty.
### `ListsTester.java`
This file contains the `ListsTester` class with the `main` method to test our `removeFirst` method:
```java
import java.util.LinkedList;
import java.util.Arrays;
public class ListsTester
{
public static void main(String[] args)
{
LinkedList<String> lst1 = new LinkedList<>(Arrays.asList("Peter", "Paul", "Mary"));
String res1 = Lists.removeFirst(lst1);
System.out.println(res1);
System.out.println("Expected: Peter");
System.out.println(lst1);
System.out.println("Expected: [Paul, Mary]");
LinkedList<String> lst2 = new LinkedList<>(Arrays.asList("A", "B", "C", "D", "E"));
String res2 = Lists.removeFirst(lst2);
System.out.println(res2);
System.out.println("Expected: A");
System.out.println(lst2);
System.out.println("Expected: [B, C, D, E]");
}
}
```
**Test Description:**
- **Test 1:** A linked list `lst1` with elements "Peter", "Paul", and "Mary" is created.
- The first element "Peter" is expected to be removed and printed.
- The modified list should contain "Paul" and "Mary".
- **Test 2:** A linked list `lst2` with elements
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