Java for AP CS A

2:20 Lesson 2 Using objects Here is the picture the whole lesson depends on. When you write String greeting equals Hello, the variab… 2:03 Lesson 3 Booleans and selection A program that always does the same thing is not much of a program. Everything that makes one interestin… 1:52 Lesson 4 Loops in Java Every loop, in every language, needs the same three parts, and a while loop spreads them out where you c… 1:52 Lesson 5 Strings and nested loops A String looks like one thing. The moment you need to count something inside it, it becomes a list of ch… 2:02 Lesson 6 Writing a class Until now you have used other people's types. Now you make your own. A class is a blueprint: it says wha… 1:49 Lesson 8 Arrays Twenty test scores and twenty variable names is a mistake waiting to happen. One name and a number is th… 2:09 Lesson 9 Array algorithms Four array jobs turn up on nearly every paper, and they are all the same shape. Sum: start at zero and a… 2:03 Lesson 10 ArrayList An array's length is frozen the moment you make it, and often you do not know how many things there will… 1:54 Lesson 11 The remove bug The safe way to keep only some items is not to remove the others — it is to build a second list. Walk th… 1:46 Lesson 12 2-D arrays A seating plan, a chessboard, a spreadsheet - none of them fit in a single row of values. A 2-D array is… 1:51 Lesson 13 Searching Finding one item in a list sounds too simple to teach. The exam asks about it because one way looks at a… 2:03 Lesson 14 Sorting You will not be asked to invent a sort. You will be asked to trace one, which means knowing exactly what… 2:02 Lesson 15 Recursion A recursive method is one that calls itself, and every single one has exactly two parts. The base case i… 1:47 Lesson 16 Text files A program that forgets everything the moment it closes is a toy. Writing to a file is the smallest step … 2:06 Lesson 17 Inheritance Two classes that share nine methods out of ten give you nine chances to fix a bug in one of them and not… 1:44 Lesson 18 Polymorphism Here is the idea, and it is worth watching rather than reading. The variable is declared as an Animal, a…