$$config title: 김한얼 공부위키 keywords: - IT $$ [기술 블로그](https://slog.gg/b/1457) [디스코드 링크](https://discord.com/invite/QN9XZAQmpw) [수업 페이지 링크](https://slog.gg/p/1227) [도커 수업 페이지](2393) $$ hide 보고 위캔에 링크,소감올리기 format $$ youtube GK3h936Co-k $$ $$ # 2021-11-09 001일차 - - git update-git-for-windows - - git init - make .git repository - - git status - check the .git status - red == not added - green == added - - git add . - ready to commit - - git config user.name "input user's name" - - git config user.email "input user's email' - - git config --global --unset-all user.name - delete user.name - - git config --global --unset-all user.email - delete user.email - if it doesn't works, go Windows certifications and delete github certification - - git commit -m "[message]" -commit with comments - - git log - check history log - - git checkout -f . - roll back to recent committed files - - git rm --cached "file_name" -r - delete files on git repository # 2021-11-10 002일차 - - git push "aka" "branch" - upload local repository to online repository - - git clone "aka" "branch" - copy online repository to local repository - - git remote add "aka" "url" - set online repository url - - git pull "aka" "branch" - merge online repository with current dir - - git push "aka" "branch" - upload local repos to online repos - - git remote remove "aka" - remove connection between local and online repository - - git pull "aka" "branch" --allow-unrelated-histories - but prefer to using clone # 2021-11-11 003일차 - Java - Class - Initializer ```java public class "name"{ "name"(type param1, type param2....){ this(param1,param2....); } } ``` - initialize parameter - heritance ```java public class "name" extends "parents"{} ``` - get parent's methods and attributes ```java super(attribute); ``` - get parent's attributes - abstract class ```java "access modifier" "return type" "name"{} ``` - abstract class can not create it's instance - abstract class can create itselves undone - Exception - try and catch ```java try{ "something" }catch("exceptionName" e){ "something" }finally{ "forced run" } ``` - throws ```java "access modifier" "type" methodName() throws "exception Name" ``` - throw errors to called method # 2021-11-12 004일차 - 없음 # 2021-11-15 005일차 https://www.youtube.com/channel/UC2nkWbaJt1KQDi2r2XclzTQ ```cmd - git config --global core.autocrlf true ``` 윈도우에서 엔터 = \r\n 맥에서 엔터 = \n 이 차이로 인한문제점을 해결 해줌 # 2021-11-16 006일차 - Java - Buffer ```java import java.io.BufferedWriter; import java.io.BufferedReader; import java.io.OutputStreamWriter; import java.io.InputStreamReader; import java.io.IOException; ``` - BufferedReader ```java BufferedReadered bf = BufferedReader(new InputStreamReader(System.in)); String s = bf.readLine(); ``` - readLine(); value that have to return is fixed to "String" - needs throws IOException on method - use StringTokenizer to divide data by blank - use nextToken() to get next value - use String.split() and assign data to Array - BufferedWriter ```java BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); String s = ""; bw.write(s+"\n"); // escape문자 bw.flush(); bw.close(); ``` - write() save data to buffer with no \n - flush() print data on buffer and get rid of the fro mbuffer. - close() make free that memory buffer uses # 2021-11-16 006일차 - Java - ArrayList ```java ArrayList name = new ArrayList(); ``` - create ArrayList - .add(component) - .get(idx) get value - .size() get ArrayList length - it's memories are flexible # 2021-11-25 013일차 - Java - HashMap ```java Map instanceName = new HashMap<>(); instanceName.put(key,value); //put data in hashmap instanceName.get(key); // get value by key ``` ```html

종류	배열	ArrayList	HashMap
생성방법	int[] arr = new int[10];	List<Integer> list = new ArrayList<>();	Map<String, Integer> map = new HashMap<>();
유연성	데이터를 10개 넣을 수 있음, 늘리는 것 불가능	신경안써도 됨(알아서 늘어남)	신경안써도 됨(알아서 늘어남)
데이터 넣을 때	arr[0] = 1;	list.add(1);	map.put("영수나이", 1);
데이터 수정할 때	arr[0] = 2;	list.set(0, 2);	map.put("영수나이", 2);
데이터 가져올 때	int data = arr[0];	int data = list.get(0);	int data = map.get("영수나이");
데이터 지울 때	불가능	list.remove(0);	map.remove("영수나이");
데이터 순회	for ( int i = 0; i < arr.length; i++ ) { System.out.println(arr[i]); }	for ( int i = 0; i < list.size(); i++ ) { System.out.println(arr.get(i)); }	for ( String key : map.keySet() ) { System.out.println(key + " : " + arr.get(key)); }

``` # 2021-11-25 013일차 - Arduino - 리모컨을 통해 노래 재생기를 제어하고, lcd까지 표시해주는 스크립트를 만듦. [링크](https://slog.gg/p/2089)