Un-tit-led

Basic

Trailing commas vs. no trailing commas

Dart        ✅ trailing commas everywhere, encouraged
JavaScript  ✅ trailing commas allowed in modern JS (ES5+)
Python      ✅ trailing commas allowed in lists and tuples
JSON        ❌ strictly forbidden, will break parsing
C / C++     ❌ not allowed in most contexts
Java        ❌ not allowed
SQL         ❌ will cause a syntax error
HTML        ❌ not applicable, different syntax entirely

The general rule of thumb is:

Modern interpreted/compiled languages — usually fine, sometimes encouraged
Data formats like JSON — never, it's a spec violation
Older strictly typed languages like Java/C — not allowed

JSON is the one that bites people the most because it looks similar to JavaScript object syntax where trailing commas ARE allowed, but JSON the format explicitly forbids them. You'll get a parse error every time.

Those CRLF warnings are harmless by the way — just Windows using \r\n for line endings vs Linux/Mac using \n. Nothing breaks, just git being informative.

Android

General

compile, target and min SDK in build.gradle.kts

compileSdk    — the version of Android SDK you're compiling AGAINST
targetSdk     — the version of Android you're optimizing/testing FOR
minSdk        — the OLDEST Android version that can install your app

    minSdk     → floor    — minimum Android version to install
    targetSdk  → ceiling  — newest Android you've tested and optimized for  
    compileSdk → tooling  — what SDK version your build tools use, irrelevant to users

minSdk→ blocks install on the lowest version.

Flutter

child takes one widget, children many
devicePixelRatio is Android's term for pixel density displayed as ratio. For example a ratio of 3.0 means 3 physical pixels for ever logical pixel which is what xxhdpi screens reports.

Java

Archived to sort

VS CODE

To change Python Interpreter:

Click on the Python version in the bottom status bar (it usually displays the version number of the Python interpreter currently in use). Alternatively, you can use the Command Palette (Ctrl+Shift+P on Windows/Linux or Cmd+Shift+P on macOS) and type "Python: Select Interpreter".
Select the interpretor in venv you just created and not any other

Flask Flaskflask run command creates an application on the local server which you can access by visiting 127.0.0.1:5000 but it can’t be deployed to the server directly this way maybe because you can’t route to that location online.

Nothing is as helpful as the documentation alone. The simple documentation helped me like 90% to deploy the app on the server. Documentation first, everything else secondary.
Make Flask Application and deploy online on render.com

Make a Github Repo and clone it
Open the Local Copy with VS Code
Make Virtual Environment	python -m venv venv
Activate Virtual Environment	.\venv\Scripts\activate
Upgrade pip	(venv)python -m pip install --upgrade pip
Install Flask	(venv)pip install flask
Install Gunicorn for deploying online	(venv)pip install gunicorn
Install python dot env	(venv)pip install python-dotenv
Extract requirements	(venv)pip freeze > requirements.txt
Edit requirements.txt:	Change == to <=
Make .gitignore file with the contents:	venv/ __pycache__
Make app.py file in root	from flask import Flask, render_template, request app = Flask(__name__) @app.route("/") def index(): return render_template('index.html')
Make templates folder and index.html	Basic HTML file.
Get out of Virtual Environment	(venv)deactivate
Test and Debug Your Code	flask run
Push Code to Github	and publish branch
Go to Render.com and add your code as Web Service	Select your branch
In the start command put (Since we named our app app and the file app) and Create Web Service	gunicorn 'app:app'

Install Pip requirements file: pip install -r requirements.txt
Flask 2.2.x supports python 3.7 and above.

yield vs. return

SQLAlchemy has a Connection Pooling mechanism by default. That means with yield you are creating a single session for each request. When you use return you are using a single database connection for all your app.

https://stackoverflow.com/questions/64763770/why-we-use-yield-to-get-sessionlocal-in-fastapi-with-sqlalchemy

FastAPI

Run FastAPI application:

uvicorn app:app --host 127.0.0.1 --port 5000

Database/Postgress/JSON

Let’s take this example:

currencies

KWD

name "Kuwaiti dinar"

symbol "د.ك"

def populate_countries():

response = requests.get('https://restcountries.com/v3.1/all')

data = response.json()

for item in data:

currencies = item.get('currencies', {})

currency_data = next(iter(currencies.values()), {})

currency_code = list(currencies)[0]

Returns the first key

Unity and C# - abandoned due to new role

TODO

TextMeshPro UI: How to add text as percentage instead of actual values as adding the text with autosize doesn’t maintain the homogenity.
Q. Is the TextMeshPro Text already a percentage?

A.No, it’s in points.

Common Screen Resolution:

Android Screen Resolution Q1’2022: https://www.antutu.com/en/doc/127152.htm

Font Asset Creator for TextMeshPro TMP

Pretty Simple:

From the menu, choose: Window > TextMesh Pro > Font Asset Creator to open the Font Asset Creator.

https://docs.unity3d.com/Packages/com.unity.textmeshpro@4.0/manual/FontAssetsCreator.html

View Post Alt+Shift Shortcut

When in rect transform, in anchor presets hold alt and/or shift to lower your burden.

Scroll Panel

Every button’s anchor should be at the center of the scroll panel.
The restriction shouldn’t be elastic as then it won’t go outside the scroll rect. It shoud be unrestricted.
Game Objects have a debug mode on top of them, use them instead of printing every debug log.

In General Tips

Always put the component as a child instead of the same component. This helps as later you can change the component as required.

Video Player Unity

Java - abandoned due to new job To Research

Non-static method 'solution(java.lang.String, int[])' cannot be referenced from a static context.

If you remove static from psvm, the run command no longer shows the option to run the java file.

Array initializer is not allowed here

When trying to send a new array already initialized to a method

Codility

HyperSkill: Java for Beginners

Paradigms/Programming Approaches:

Imperative: You provide step by step instructions on how to do it.

Procedural: Procedure Calls. List of instructions. Java.
Object Oriented: Collection of classes.
Parallel Processing: Divide and Conquer.

Declarative: You tell the system what you need and it comes up with a way to do it.

Logic: Formal Logic. Basic Statements: Facts, Rules and Queries.
Functional: In Procedural, the original data is changed. Not here.
Database: Working with data.

HackerRank - JAVA

One popular way to read input from stdin is by using the Scanner class and specifying the Input Stream as System.in. For example:

Scanner scanner = new Scanner(System.in);

String myString = scanner.next();

int myInt = scanner.nextInt();

scanner.close();

System.out.println("myString is: " + myString);

System.out.println("myInt is: " + myInt);

The code above creates a Scanner object named and uses it to read a String and an int. It then closes the Scanner object because there is no more input to read, and prints to stdout using System.out.println(String).
Close scanner with scanner.close
Standard input is a stream from which a program reads its input data. The program requests data transfers by use of the read operation.
Standard output is a stream to which a program writes its output data. The program requests data transfer with the write operation.
Scanner Class: Java

A simple text scanner which can parse primitive types and strings using regular expressions.
Scanner breaks its input into tokens using a delimiter pattern which by default matches whitespaces. The resulting token may then be converted into values of different types using the various next methods.
If you use the nextLine() method immediately following the nextInt() method, recall that nextInt() reads integer tokens; because of this, the last newline character for that line of integer input is still queued in the input buffer and the next nextLine() will be reading the remainder of the integer line (which is empty).

Replace next() with nextLine():

This will fail if any next() call precedes the nextLine() call. The right answer is not to use nextLine (you rarely need nextLine); instead, fix your scanner's delimiter: call .useDelimiter("\r?\n"); on it immediately after its creation.

\t: tab
\r: carriage return
\n: line feed (new line)
\a: system bell

To scan the next string: scanner.next();
To scan the next int: scanner.nextInt();
Number of characters in a string: string.length();
Concatenate strings with +
Convert integer to string with: String.valueOf(x);Math.Pow returns double and not int.

// convert into int

int value = (int)data;

Always convert double to into before comparing it to int otherwise it gives the wrong error. To look more into it later.
Instead of manually typing down the values of the maximum int or max long just the constants in the java package known as:

Long.MAX_VALUE
Integer.MAX_VALUE

Static Initialization Blocks let you initialize the variable outside the main method for use by every method. More details here: https://docs.oracle.com/javase/tutorial/java/javaOO/initial.html
Switch: Multi-constant case labels supported from Java 14 onwards only.
Compare two string like in dictionary/lexicographically:

A.compareTo(B);

CodeAcademy

Inheriting the constructor

If you’re inheriting the superclass, you have to use super() construct only if the superclass has no default construct. If the superclass has a construct, you can actually use this.* to initialize the subclass.
Access Modifiers

Modifier	Class	Package	Child Class	Global
public	✅	✅	✅	✅
protected	✅	✅	✅	❌
no modifier	✅	✅	❌	❌
private	✅	❌	❌	❌

There is another access modifier we can use to keep a parent class member accessible to its child classes and to files in the package it’s contained in — and otherwise private: protected
If we add final after a parent class method’s access modifier, we disallow any child classes from changing that method. This is helpful in limiting bugs that might occur from modifying a particular method.
Polymorphism:

For example, the built-in operator + can be used for both doubles and ints. To the computer, the + means something like addDouble() for one and addInt() for the other, but the creators of Java (and of other languages) didn’t want to burden us as developers with recalling each individual method.
Note that the reverse situation is not true; you cannot use a generic parent class instance where a child class instance is required. So an Orange can be used as a Fruit, but a Fruit cannot be used as an Orange.

You may have also noticed the @Override keyword. This annotation informs the compiler that we want to override a method in the parent class. If the method doesn’t exist in the parent class, we’ll get a helpful error when we compile the program.

Learnt from Interview Tests

Developers often confuse the String.length() method with the array.length property.
How to declare a predefined size integer array:

int[] finalArray = new int[finalRangeSize];

IDEs Apache Netbeans IDE 14

sout and tab to insert the system out code: System.out.println("");
Change package name by right clicking the package-> Refactor and then clicking on Rename.
Ctrl+Alt+L : Format the code
When you click on the ending curly brace, it shows where the code has actually begun in the top part which is very very convenient.

Soft Skills People Lie

Start considering the possibility that your senior/colleague might just be straight up lying about knowing something when they know nothing about it.

I have seen this happen a lot in my career. Instead of admitting that they don't know what they are talking about, they like to make up stuff and if you take their made-up stuff seriously, it will cause hours of frustration for you trying to conjure up a figment of their imagination to actual work.

#work #career

ni6hant's Developer Notebook

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