https://course.khoury.northeastern.edu/cs2510a/lab7.html
Lab 7: Working with ArrayLists and Mutable worlds
working withlabmutableworlds
https://www.codecademy.com/learn/java-arrays-and-loops/modules/learn-java-arrays-and-arraylists/cheatsheet
Java Arrays and Loops: Arrays and ArrayLists Cheatsheet | Codecademy
java arraysloopscheatsheetcodecademy
https://www.codecademy.com/learn/spring-apis-java-i/modules/learn-java-arrays-and-arraylists/cheatsheet
Java I: Arrays and ArrayLists Cheatsheet | Codecademy
javaarrayscheatsheetcodecademy