すべてのカテゴリ

何度か触って遊んでみた経験はあるpythonなのですが、業務ではRailsやPHP等がメインだったため、本格的に触る機会もなく、このところはコンサル系にシフトしていたため、プログラミングもPHPで短いものを書くぐらいになっていてプログラミングから遠ざかっていた最近ですが、スクールのWebクリエイター育成講座でJavaScripitをいじっていると、だんだんと久しぶりにプログラミングしたいというモヤモヤが...(^^;実際そんなに触っている時間がなさそうだったので、Automachefで朝臣dねみたりしながら気をそらしていたのですが...python教えてほしいというリクエストがきちゃった...いや、自分も遊びで何度かいじったぐらいで、教えられるレベルにはないと思うんだけど...というわけで、再勉強というか、最初から勉強しなおそうかと思います。息子が学校の宿題やっている横で、パパが何か新しいものを勉強している様子を見せるというのも大事だろうし...頑張るっすよー

Appleから2020年にリリースされたMacは、これまでのMacとは大きく変わった点があります。それはCPUがx86アーキテクチャから、ARMアーキテクチャに変更されたことです。これにより、こんな点が改善されてめちゃくちゃMacが優位に立っています。改善１：消費電力の効率化改善２：処理性能の向上改善３：iPhone, iPadとのアプリ共有x86とARMは何がどう違うの？アーキテクチャが違うとはいえ、同じCPUじゃないの？何が違うの？という疑問も出てくるかと思います。結論、同じプログラムを別なCPUで動かすことはできません。なぜなら、CPUアーキテクチャが異なると、コンピュータに命令する機械語が全く異なるからです。機械語は、CPUに対して命令するための仕様です。この仕様は、各社個別に定義されているので、機械語の書き方もバラバラになっています。ARMアーキテクチャでも使えるようにするためには、ARMに対応した機械語にビルドできるソフトウェア（コンパイラ）を使う必要があります。それだけでなく、ARM版でも正しく動作するのか全面的にテストし治す必要もあるので、アーキテクチャの移行はソフトウェアの規模が大きいほど大変な再開発となります。ARMに変わったことによる悪影響プログラマにとって最も悪い影響は「Dockerが使えなくなった」点です。CPUアーキテクチャの変更により、x86アーキテクチャに依存する機能がARMアーキテクチャでは動作しない状況が続いていました。DockerがApple silicon対応完了ずっとM1 MacではDockerが動作しない状況が続いていましたが、202

１．About logI think that the purpose of outputting the log is as follows.・To confirm whether the process was performed when　testing the program.・To log a message when an error occurs and use it　for investigation.・To record the processing date and time and access　status to check for hacking."Log4j" is a representative Java log output, and it isone of the Java logging frameworks. But I think theLogger class in the java.util.logging package is moresuitable for beginners. So let's take a look at theLogger class this time.２．java.util.logging.LoggerThe following program explains how to output logsusing the Logger class.-------------------------- LogTest.java -------------------------------------imp

１．About FileWriter classThis time I will talk about file output. There is a class calledFileWriter in the java.io package, so let's first see how touse this class.----------------------- WriteTest.java -------------------------------------import java.io.*;public class WriteTest {    public static void main(String[] args) throws Exception {        FileWriter fw = null;        try {            File file = new File("c:¥¥test¥¥test.txt");            fw = new FileWriter(file);            fw.write("Hello world");        } catch(FileNotFoundException e) {            System.out.println(e);        } catch (IOException e) {            System.out.println(e);        } finally {             // Close the

１．About BufferedReader classThis is a continuation of the previous file input. TheFileReader class is inefficient because it reads charactersfrom the file one by one. The java.io package provides aBufferedReader class that reads line by line from a file,so let's see how to use this class with the following program.----------------------- ReadTest2.java -------------------------------------import java.io.*;public class ReadTest2 {    public static void main(String[] args) throws Exception {        BufferedReader br = null;        try {            File file = new File("c:¥¥test¥¥sample.txt");            FileReader fr = new FileReader(file);            br = new BufferedReader(fr);            St

About file inputSince it is common to manage data with a DB, it is themainstream to acquire or register data in a DB using SQL.It will be introduced in another time.In addition, there are also scenes where you perform fileoperations from Java, such as receiving a file (CSV file, etc.)from the outside and importing it into the DB, or outputtingthe contents of the DB to a file and providing it to the outside.This time, I will talk about the file input.There are the following two types of file input / output in Java.・Byte stream・Character stream8 bits = 1 byte, and the byte stream inputs / outputs filesbyte by byte. The character stream inputs / outputs filescharacter by character. This time,

１．Classes for character stringThere are many situations where you handle characters.Classes are provided in Java that are useful in suchcases, so I will introduce some of them.（１）StringThe first is the String class in the java.lang package.When you use the class of java.lang package, it is notnecessary to write "import java.lang.*;". This is becauseit is implicitly imported at compile.Also, String can create an object without new.    String strTmp = "test";If you enclose the string in double quotes like this,it will be treated as an object.Next, I will introduce the methods that I often use in String.①equalsCompares strings to each other and returns true if they match,false if they don't. Fo

１．About Map of collection classFollowing List, this time I will introduce Map from the utility "java.util". You store a combination of key and value in Mapas one data. You use the key if you want to retrieve thevalue from the Map.Map also has several classes, so I will explain about"HashMap", "TreeMap", and "LinkedHashMap" in this time.（１）HashMapThis is a standard Map. You cannot register the duplicatekeys. Also, the elements (key and value sets) are notarranged in the order in which they were registered.To use it, specify the type as shown below when you new.For example,  HashMap<String,String> map = new HashMap<String,String>();or  HashMap<Integer,String> map = new HashMa

１．About List of collection classI will talk about frequently used collection classes from theutility "java.util" provided by Java. This time about List.In the List, the elements are arranged in order.If you want to use an array, you need to specify the numberof elements in advance, but in the case of List, you can useList without specifying it.There are two types of List, "ArrayList" and "LinkedList".The program below uses ArrayList.------------------------- ListTest.java -----------------------------------------import java.util.*; public class ListTest {  public static void main(String args[]) throws Exception{   ArrayList<String> list = new ArrayList<String>();   // Measureme

About inheritanceTriangle is a kind of figure, so I created a parent classof Triangle class. That is the Figure class below.------------------------ Figure.java ----------------------------public class Figure {  // Member variables  private int iArea;  // getter  public int getArea() {   return this.iArea;  }  // setter  public void setArea(int area) {   this.iArea = area;  } } ------------------------------------------------------------------------------------------- Triangle.java ----------------------------public class Triangle extends Figure{  // Member variables  private int iBottom;  private int iHeight;  // Constructor  public Triangle(int bottom, int height) {   this.iBottom = bott

１．About stdinTriangle.java I created yesterday could only calculatethe area of a triangle with a base of 6 and a height of 4.Let's improve it so that we can calculate the arearegardless of the value of the base and height.The improved program is as follows.----------------------------- Triangle.java ------------------------------import java.util.Scanner;public class Triangle {    public static void main(String[] args) throws Exception {        System.out.println("How long is the bottom?");        Scanner sc = new Scanner(System.in);        int iBottom = sc.nextInt();           // Input the bottom.        System.out.println("How long is the height?");        int iHeight = sc.nextInt();       

A happy new year！ I look forward to working with youagain this year. I hope I can do the following things this year.■Plans・Programming with Java・I will try to make a Big or Small game with Java.・Measures for the Fundamental Information Technology　Engineer Examination (around March)In summary, I will introduce programming with Javalittle by little from today. First, take a look at thesample program.----------------------------- Sample.java ----------------------------------------public class Sample {    public static void main(String[] args) throws Exception {        int x = 6;        int y = 4;        int z = x * y / 2;        System.out.println(z);    }}-------------------------------------

人工知能（AI）は、コンピューターが人間と同様のような思考や行動を行うことを可能にする技術です。AIは、明らかなタスクや課題を効率的に実行したり、新しいタスクを学習したり、複雑な状況を分析して最適な行動を取ったりすることができます。