Access Modifier

            | Class | Package | Subclass | Subclass | World
            |       |         |(same pkg)|(diff pkg)| 
————————————+———————+—————————+——————————+——————————+————————
public      |   +   |    +    |    +     |     +    |   +     
————————————+———————+—————————+——————————+——————————+————————
protected   |   +   |    +    |    +     |     +    |   o     
————————————+———————+—————————+——————————+——————————+————————
no modifier |   +   |    +    |    +     |     o    |   o
————————————+———————+—————————+——————————+——————————+————————
private     |   +   |    o    |    o     |     o    |   o

+ : accessible
o : not accessible

Constructor:

Public class TrieTree
{
    char ch;
    //constructor, noted that no return type here. No need for constructor.
    public TrieTree()
    {

    }

    public TrieTree(char c)
    {
        ch = c;
    }
}

Initialize Array

int[] data;
data = new int[] {10,20,30,40,50,60,71,80,90,91};

//OR
int[] data = new int[20];

List to Array

Inner Class Types