ArrayList

Basics

After importing the package, I'm creating an arraylist of String type called "math". I'm adding two lists to math, "basic" and "advanced". Basic has the 4 basic math operations (add, subtract, multiply, divide) while advanced has more complex ones such as square roots and exponents. I'm using "math.addAll();" to add both lists to the ArrayList, then printing it as the original.

import java.util.ArrayList; // import package

ArrayList<String> math = new ArrayList<String>(); // new arraylist

List<String> basic = new ArrayList<String>(); // 2 lists to be added to arraylist
List<String> advanced = new ArrayList<String>();

basic.add("addition"); // adding these items to basic list
basic.add("subtraction");
basic.add("multiplication");
basic.add("division");

advanced.add("square root"); // adding to advanced list
advanced.add("exponent");
advanced.add("logarithm");

math.addAll(basic);
math.addAll(advanced); // adding 2 lists to math

System.out.println("Original: " + math); // math has all items from both

Original: [addition, subtraction, multiplication, division, square root, exponent, logarithm]

Modifying

I used the removeAll for the advanced list to show which operations the abacus can't do, and printed the new list as basic operations.

math.removeAll(advanced);
System.out.println("Basics: " + math);

Basics: [addition, subtraction, multiplication, division]

Removing the last element (number 3) from the arraylist and printing it

math.remove(3);
System.out.println("Remove last element: " + math);

Remove last element: [addition, subtraction, multiplication]

Removing all items from the array so it is now empty

math.clear();
System.out.println("Cleared: " + math);

Cleared: []