<attr name="customText" format="reference" />
<attr name="customTextSize" format="dimension" />

<declare-styleable name="CustomButton">
	<attr name="customText" />
	<attr name="customTextSize" />
</declare-styleable>

public final class CustomButton extends LinearLayout {
	...
}

public final class CustomButton extends LinearLayout {
    public CustomButton(@NonNull Context context) {
        super(context);
    }

    public CustomButton(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public CustomButton(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }
}

public final class CustomButton extends LinearLayout {
    // Attributes
    private String customText;
    private int customTextSize = 999;

    // Views
    private TextView customButtonTvText;

    public CustomButton(@NonNull Context context) {
        super(context);
        init(context);
    }

    public CustomButton(@NonNull Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        parseAttributes(context, attrs);
        init(context);
    }

    public CustomButton(@NonNull Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        parseAttributes(context, attrs);
        init(context);
    }

    private void parseAttributes(@NonNull Context context, @Nullable AttributeSet attrs) {
        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.CustomButton);

        try {
            if (typedArray.hasValue(R.styleable.CustomButton_text))
                customText = typedArray.getString(R.styleable.CustomButton_customText);
            if (typedArray.hasValue(R.styleable.CustomButton_textSize))
                customTextSize = typedArray.getDimensionPixelSize(R.styleable.CustomButton_customTextSize, 0);
        } catch (Throwable t) {
            t.printStackTrace();
        } finally {
            try {
                typedArray.recycle();
            } catch (Throwable t) {
                t.printStackTrace();
            }
        }
    }

    private void initViews() {
        customButtonTvText = findViewById(R.id.custom_button_tv_text);
    }

    private void init(@NonNull Context context) {
        inflate(context, R.layout.button_custom, CustomButton.this);
        initViews();

        if (customText != null) customButtonTvText.setText(customText);
        if (customTextSize != 999) customButtonTvText.setTextSize(TypedValue.COMPLEX_UNIT_PX, customTextSize);
    }

    public void setText(CharSequence text) {
        customButtonTvText.setText(text);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<merge xmlns:android="http://schemas.android.com/apk/res/android">

    <TextView
        android:id="@+id/custom_button_tv_text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ellipsize="end"
        android:gravity="center"
        android:singleLine="true"
        android:textAllCaps="true"
        android:textColor="@color/white"
        android:textSize="18sp" />
</merge>

<com.example.app.CustomButton
	android:layout_width="match_parent"
	android:layout_height="wrap_content"
	android:layout_margin="12dp"
	app:customText="Tamam"
	app:customTextSize="18sp" />

class Game {
    // bu classtan bir nesne oluşturulduğu zaman listener varsayılan olarak null tanımlanıyor
    onTick = null;

    constructor(id, players, time) {
        this.id = id;
        this.players = players;
        this.time = time;
    }

    // oyunu başlatıyoruz
    start() {
        var interval = setInterval(() => {
            if (this.time > 0) {
                this.time -= 1;
            }

            // burada listenerı tetikliyoruz
            // her bir saniyede bu listener tetiklenecek
            if (this.onTick != null) this.onTick();
        }, 1000);
    }

    // dışarıdan bu fonksiyonu kullanarak listener oluşturuyoruz
    setOnTickListener(l) {
        // bu kontrolü listener birden fazla kere tanımlanmasın diye koyuyoruz
        if (this.onTick != null) return;
        this.onTick = l;
    }
}

module.exports = Game;

// game.model.js dosyamızı çağırıyoruz
const Game = require('./game.model.js');

// yeni bir nesne oluşturuyoruz
var game = new Game('18815616', null, 30);

// bu nesneye özel bir listener oluşturuyoruz
game.setOnTickListener(() => {
    console.log('game time: ' + game.time);
});

game.start();

game time: 29
game time: 28
game time: 27
game time: 26
game time: 25
game time: 24
game time: 23
game time: 22
game time: 21

npm install mysql

const mysql = require('mysql');

// database ayarları
const db = mysql.createConnection({
    host: 'localhost',
    user: 'root',
    password: 'password',
    database: 'database_name'
});

// yukarıdaki bilgilere göre database bağlanıyoruz
db.connect(function (err) {
    // eğer bir hata oluşursa programı durdurup hatayı konsola yazdıracak
    if (err) throw err;

    // başarılı bir şekilde bağlandığını konsola yazdırıyoruz
    console.log('connection successful');
});

// db objesini export ediyoruz ki bu dosyayı çağırdığımız yerde sorgular çalıştırabilelim
module.exports = db;

// database dosyamızı çağırıyoruz
const db = require('./database.js');

// sorgu çalıştırıyoruz
db.query(`SELECT * FROM players WHERE id = '107861148515'`, (err, result) => {
    if (err) throw err;
    var row = result[0];

    if (result.length > 0) {
        console.log(row);
    } else {
        console.log('player not found');
    }
});

<?xml version="1.0" encoding="utf-8"?>
<ripple xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:color="#5183c1">

    <item>
        <shape>
            <corners android:radius="4dp" />
            <solid android:color="#135790" />
        </shape>
    </item>
</ripple>

<Button
    android:id="@+id/button"
	android:layout_width="wrap_content"
	android:layout_height="wrap_content"
	android:text="Buton"
	android:background="@drawable/bg_button"
	/>

https://example.xyz/api  ->  http://example.xyz/api

<?xml version="1.0" encoding="utf-8"?>
<manifest>
    <uses-permission android:name="android.permission.INTERNET" />
    <application
        ...
        ...
        android:usesCleartextTraffic="true"
        ...
    </application>
</manifest>

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <domain-config cleartextTrafficPermitted="true">
        <domain includeSubdomains="true">example.xyz</domain>
        <domain includeSubdomains="true">api.example.xyz</domain>
    </domain-config>
</network-security-config>

<?xml version="1.0" encoding="utf-8"?>
<manifest>
    <uses-permission android:name="android.permission.INTERNET" />
    <application
        ...
        ...
        android:networkSecurityConfig="@xml/network_security_config"
        ...
    </application>
</manifest>

#include <stdio.h>

int main() {
	int sayi1, sayi2, sonuc = 0;
	
	printf("sayi1 : ");
	scanf("%d", &sayi1);
	
	printf("sayi2 : ");
	scanf("%d", &sayi2);
	
	for(int x = 0; x < sayi2; x++) {
		sonuc = sonuc + sayi1;
	}
	
	printf("sonuc : %d", sonuc);
}

flutter pub add shared_preferences

import 'package:shared_preferences/shared_preferences.dart';

var sharedPreferences = await SharedPreferences.getInstance();

var sharedPreferences = await SharedPreferences.getInstance();
sharedPreferences.setString(key, value);

Future<void> setString(String key, String value) async {
    var sharedPreferences = await SharedPreferences.getInstance();
    sharedPreferences.setString(key, value);
}

//kullanimi
setString('kullanici_adi', 'hakans');

Future<String> getString(String key) async {
    var sharedPreferences = await SharedPreferences.getInstance();
    return sharedPreferences.getString(key) ?? 'none';
}

//kullanimi
getString('kullanici_adi').then(((value) {
    setState(() {
        kullanici_adi = value;
    });
}));

import 'package:shared_preferences/shared_preferences.dart';

class BasicPref {
  Future<void> setInt(String key, int value) async {
    var sharedPreferences = await SharedPreferences.getInstance();
    sharedPreferences.setInt(key, value);
  }

  Future<void> setString(String key, String value) async {
    var sharedPreferences = await SharedPreferences.getInstance();
    sharedPreferences.setString(key, value);
  }

  Future<void> setBool(String key, bool value) async {
    var sharedPreferences = await SharedPreferences.getInstance();
    sharedPreferences.setBool(key, value);
  }

  Future<int> getInt(String key) async {
    var sharedPreferences = await SharedPreferences.getInstance();
    return sharedPreferences.getInt(key) ?? 0;
  }

  Future<String> getString(String key) async {
    var sharedPreferences = await SharedPreferences.getInstance();
    return sharedPreferences.getString(key) ?? 'none';
  }

  Future<bool> getBool(String key) async {
    var sharedPreferences = await SharedPreferences.getInstance();
    return sharedPreferences.getBool(key) ?? false;
  }
}

final basicPref = BasicPref();

android {
    ...
    dataBinding {
        enabled = true
    }
}

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools">

    <LinearLayout
        android:id="@+id/example_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        android:orientation="vertical"
        tools:context=".MainActivity">

        <TextView
            android:id="@+id/hello_world_text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:gravity="center"
            android:text="Hello World" />
    </LinearLayout>
</layout>

ActivityMainBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_main);

package com.hknsoft.databinding;

import androidx.appcompat.app.AppCompatActivity;
import androidx.databinding.DataBindingUtil;

import android.os.Bundle;
import android.view.View;

import com.hknsoft.databinding.databinding.ActivityMainBinding;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        ActivityMainBinding binding = DataBindingUtil.setContentView(this, R.layout.activity_main);

        binding.helloWorldText.setText("Deneme123");

        binding.exampleLayout.setVisibility(View.VISIBLE);
    }
}