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【 Android Development for Beginners】 Lesson 3A : Object Oriented Programming - 3

This Notes is according to the udacity free course :

Android Development for Beginners

Lesson 3A : Object Oriented Programming

Resources









What are Java objects




There are 2 easy samples for you to understand what is Java class ?
These are the most important part of this section.





How to create object

1. create object with constructor(regular style)


2. create object with factory methods (need to check out the object documentation)


The quiz focus on too much detail,so I provide the answer for you to check.
TextView textView = new TextView(context);
ImageView img = new ImageView(context);
ToggleButton button = new ToggleButton(context);
Toast toast = Toast.makeText(context, text, duration);


The different between object and class
reference:diffen

class is like a blue map for you to construct object
class can include many state and methods


留言

這個網誌中的熱門文章

R 語言翻轉教室-2

Lesson 2 :  Object 入門操作 R的object結構是依照針對資料結構分析所設計的。 最簡單的object 即為 一串數字  。 一般程式語言最簡單的object則為 一個數字。 若要儲存一個向量到變數“x”當中: example: 要用R 建立一個內容為10.4, 5.6, 3.1和6.4的向量, 最常用的方式就是輸入:`c(10.4, 5.6, 3.1, 6.4)` 請同學依照這樣的語法建立一個這樣的向量,並且把它存為變數x。 Ans:x <- c(10.4, 5.6, 3.1, 6.4) 欲求出變數向量的最大最小值: c(min(x), max(x)) 欲求出範圍: range(x) 欲求出向量平均: sum(x)/length(x)(總和/向量長度)

R語言翻轉教室-3【01-RBasic-03-Data-Structure-Object】

*R的物件結構 組成R語言的基本物件結構為「向量」。 向量物件有兩個很重要的屬性: `mode`和`length`。 `mode`代表這個向量的值型態,總共有:`logical`、`integer`、`numeric`、`complex`、`character`和`raw`。 `length`則代表這個向量中值的個數。 list可以裝所有R的物件 所有的R物件都有「屬性」 所有R 物件的attributes都是帶有名字的list。 本課程筆記,出處: R語言翻轉教室 回家作業: 連結

【 Android Development for Beginners】 Lesson 3A : Object Oriented Programming - 4

(I think Lesson 3A is the most important but also the most difficult part for beginner so far ) This Notes is according to the udacity free course : Android Development for Beginners Lesson 3A : Object Oriented Programming Call Method on an objects If We want to call a method on an object object variable name . method name ( input argument ); ex: titleTextView.setText("News"); You need to make sure you put a right object so you can call the method