Week 4 Hacks

Linked Lists

import java.util.LinkedList;

LinkedList<String> testlink = new LinkedList<String>();

testlink.add("Strings");
testlink.add("Data");
testlink.add("BST");

System.out.println(testlink)

[Strings, Data, BST]

testlink.remove(); 
System.out.println(testlink)

[Data, BST]

testlink.clear();
System.out.println(testlink)

[]

System.out.println(testlink.getFirst());
System.out.println(testlink.getLast());

---------------------------------------------------------------------------
java.util.NoSuchElementException: null
	at java.base/java.util.LinkedList.getFirst(LinkedList.java:248)
	at .(#26:1)

Queues

Queue<String> Articles = new LinkedList<String>();

Articles.add("BST Tutorial");
Articles.add("Checkpoint 1");
Articles.add("Wrapper Classes");

System.out.println(Articles);

[BST Tutorial, Checkpoint 1, Wrapper Classes]

Articles.poll(); 
System.out.println(Articles);

System.out.println(Articles.contains("BST Tutorial"));

[Checkpoint 1, Wrapper Classes]
false

Stacks

import java.util.Stack;
Stack<String> tags = new Stack<String>();

tags.add("C++");
tags.add("Java");
tags.add("HTML");
tags.add("Javascript");

System.out.println(tags);

[C++, Java, HTML, Javascript]

System.out.println(tags.pop()); 
System.out.println(tags);
System.out.println(tags.set(1, "Python")); 
System.out.println(tags.size());

Javascript
[C++, Java, HTML]
Java
3

Collectables

public class CancodeUser<T> {
    private T user; 
    
    public CancodeUser(T user) {
       this.user = user;
    }
    
    public T getUser() {
       return user;
    }
    
    public void setUser(T user) {
       this.user = user;
    }
    
    public static void main(String[] args) { 
       CancodeUser<String> user1 = new CancodeUser<>("Sanjay B");
       CancodeUser<String> user2 = new CancodeUser<>("Evan Y");
       CancodeUser<String> user3 = new CancodeUser<>("Lionel Messi");
 
       System.out.println(user1.getUser()); 
       System.out.println(user2.getUser());
       System.out.println(user3.getUser());
    }
 }
CancodeUser.main(null);

Sanjay B
Evan Y
Lionel Messi