How do you create a FIFO collection using Java?

Answer 1

There's a great class called LinkedList that implements the Queue interface. To get an instance of it, use the following code snippet:

import java.util.*;

Queue queue = new LinkedList<T>();

where T is the type of the objects that will go in the queue. Remember the parentheses, as they drove me crazy during one memorable day working out why exactly that same line, minus the parentheses, kept on throwing me a rather unintelligible error.

Example:

Queue<String> q = new java.util.LinkedList<String>()

q.add("a")

q.add("b")

q.add("c")

Calling q.getFirst() returns the value "a".

Likewise, to create a Last-in first out (LIFO) collection, you use a Stack (java.util.Stack).