DEV Community: Biswajit Porel

Give me one android code and then explain what is what

Biswajit Porel — Tue, 04 Aug 2026 06:15:22 +0000

Great idea. Let's start with one of the simplest Android apps: a button that changes the text on the screen. This will introduce you to the basic building blocks of Android development.

`MainActivity.kt` (Kotlin)

package com.example.myfirstapp

import android.os.Bundle
import android.widget.Button
import android.widget.TextView
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_main)

        val textView = findViewById<TextView>(R.id.textView)
        val button = findViewById<Button>(R.id.button)

        button.setOnClickListener {
            textView.text = "Hello, Kotlin!"
        }
    }
}

`activity_main.xml` (The Screen Layout)

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:orientation="vertical">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Welcome!"
        android:textSize="24sp"/>

    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Click Me"/>

</LinearLayout>

Now let's explain every part

1. `package`

package com.example.myfirstapp

This tells Android which project this file belongs to.

Think of it like your home address.

2. `import`

import android.widget.Button
import android.widget.TextView

Imports bring ready-made Android classes into your code.

Button → creates a button.
TextView → displays text.
AppCompatActivity → the base screen of your app.

3. Class

class MainActivity : AppCompatActivity()

Every Android screen is called an Activity.

This line creates your app's first screen.

4. `onCreate()`

override fun onCreate(savedInstanceState: Bundle?)

This function runs when the screen opens.

Imagine opening YouTube. Everything you see is created here.

5. `super.onCreate()`

super.onCreate(savedInstanceState)

This tells Android to do its normal setup before your own code runs.

6. `setContentView`

setContentView(R.layout.activity_main)

This loads the XML layout.

Without this line, your app would show a blank screen.

7. `findViewById`

val textView = findViewById<TextView>(R.id.textView)

This connects your Kotlin code to the TextView in the XML layout.

R.id.textView refers to:

android:id="@+id/textView"

8. `val`

val button = ...

val means a variable whose reference won't be reassigned.

Example:

val age = 25

age always refers to that value unless you create a new variable.

9. Button Click

button.setOnClickListener {

This means:

"When the button is clicked, run the code inside these braces."

10. Change Text

textView.text = "Hello, Kotlin!"

This changes the text shown on the screen.

Initially:

Welcome!

After clicking:

Hello, Kotlin!

Understanding the XML

`LinearLayout`

<LinearLayout>

A layout is a container that holds other UI elements.

LinearLayout arranges them in a line.

`orientation="vertical"`

android:orientation="vertical"

This stacks items from top to bottom.

Like this:

Welcome!

Click Me

If it were "horizontal":

Welcome!   Click Me

`TextView`

<TextView

Displays text on the screen.

`Button`

<Button

Creates a button that users can tap.

`android:id`

android:id="@+id/button"

This gives the button a unique name so your Kotlin code can find it.

`android:text`

android:text="Click Me"

This is the label shown on the button.

`layout_width`

android:layout_width="wrap_content"

wrap_content means the view is only as wide as it needs to be.

Other common value:

match_parent

which makes it fill the available width.

What happens when you run this app?

The app starts.
onCreate() runs.
activity_main.xml is displayed.
You see:

Welcome!
Click Me button
1. You tap the button.
2. The text changes to: Hello, Kotlin!

Key things to learn from this example

Activity → A screen in your app.
XML → Describes what the screen looks like.
Kotlin → Controls how the app behaves.
Button → Receives user input.
TextView → Displays text.
ID → Connects XML elements to Kotlin code.
Click Listener → Runs code when a button is tapped.

This small app demonstrates the core pattern you'll use in almost every Android app: define the interface in XML, then write Kotlin code to respond to user actions.

how to leARN KOTLIN

Biswajit Porel — Mon, 03 Aug 2026 18:09:33 +0000

The best way to learn Kotlin is by writing code every day, not by watching hours of videos.

Here's a beginner-friendly roadmap.

Step 1: Learn Kotlin basics (1 week)

Learn these topics in order:

Variables (val and var)
Data types (Int, String, Double, Boolean)
Input and output
Operators (+, -, *, /)
if / else
when
Loops (for, while)
Functions
Lists
Classes and Objects

Don't move on until you can write small programs using each topic.

Step 2: Practice with tiny programs

After each topic, create something simple:

Print "Hello World"
Add two numbers
Find the largest of three numbers
Check if a number is even or odd
Build a multiplication table
Create a simple calculator

Step 3: Use free resources

I recommend these:

Kotlin Official Documentation – The official guide.
Kotlin Playground – Write and run Kotlin code in your browser without installing anything.
Google Android Kotlin Basics Course – Free course designed for beginners.

Step 4: Start Android development

Once you're comfortable with Kotlin basics, begin building Android apps in Android Studio.

Start with:

Calculator
BMI Calculator
To-Do List
Notes App

My teaching plan for you

Since you've said you're a complete beginner, I can teach you from zero.

We'll have lessons like this:

Lesson 1

What is Kotlin?
Install Android Studio
Your first program: Hello, World!

Lesson 2

Variables
Data types
Mini exercises

Lesson 3

if / else
Build an Even/Odd checker

Lesson 4

Loops
Multiplication table app

By the end of the first month, you'll have written real Kotlin code and built your first Android app instead of only watching tutorials.

I can act like a personal instructor and guide you one lesson at a time, checking your understanding before moving to the next topic.

How much time it will take if i start from scratch on android studio when i am a complete beginner

Biswajit Porel — Mon, 03 Aug 2026 18:03:58 +0000

If you're a complete beginner and you study consistently, here's a realistic timeline:

Time	What you'll be able to do
1 week	Understand Kotlin basics and create simple console programs.
2–4 weeks	Build simple Android apps like a calculator, unit converter, or tip calculator.
2–3 months	Build apps with multiple screens, save data locally, and create a decent user interface.
4–6 months	Build real apps with login, databases, internet APIs, notifications, and publish-ready features.
6–12 months	Be capable of building and publishing professional-quality Android apps independently.

If you study 1 hour every day

After 30 days: You'll have built 2–3 simple apps.
After 90 days: You'll be comfortable building useful Android apps.
After 6 months: You can start creating apps that people might actually use.

If you study 2–3 hours every day

You could reach the same level in about 3–4 months.

Since you told me you're starting from scratch

I wouldn't overwhelm you with theory. Instead, we'd learn by building.

Here's the order I'd teach you:

Install Android Studio.
Learn the absolute basics of Kotlin.
Build a Calculator app.
Build a To-Do app.
Build a Notes app.
Learn databases.
Learn APIs.
Build your own original app idea.

Every project would introduce just a few new concepts, so you're always learning by doing.

The most important thing is consistency. Even 1 hour every day is enough to make steady progress. Most beginners quit because they try to learn everything at once. Building small apps one by one is a much more effective approach.

Which is completely free of cost emergent or android studio?????

Biswajit Porel — Mon, 03 Aug 2026 18:01:40 +0000

If your goal is 100% free app development, here's the answer:

✅ Android Studio

Free forever to download and use.
No monthly limits.
No credit system.
You can build unlimited Android apps. (Android Developers)

⚠️ Emergent

Has a free plan, but it is not unlimited.
The free plan includes 10 AI credits per month.
After you use those credits, you'll need to wait for them to reset or upgrade to a paid plan. Some advanced mobile app features also require a paid subscription. (Emergent)

My recommendation for you

Since you mentioned you want to start completely free of cost, I recommend:

✅ Android Studio as your main development tool.
✅ Use AI assistants like ChatGPT to help you write and understand code.
✅ Optionally try Emergent's free tier to experiment, but don't rely on it for long-term development because of the credit limits.

With Android Studio, you can build as many apps as you want without paying anything. The only common cost comes later, if you decide to publish your app on the Google Play Store (Google charges a one-time developer registration fee).

Since you're starting from scratch, I can teach you Android Studio from Day 1 and help you build your first app step by step without requiring any paid software.

Is emergent better than android studio

Biswajit Porel — Mon, 03 Aug 2026 17:57:55 +0000

The short answer is: No. Emergent is not better than Android Studio—they serve different purposes.

Here's a comparison:

Emergent	Android Studio
AI builds much of the app for you	You build the app yourself (with coding)
Very fast for prototypes	Best for professional Android development
Beginner-friendly	Steeper learning curve
Limited by what the AI can generate	Full control over every feature
Good for MVPs and simple apps	Best for complex, production-ready apps
May require prompt refinement	Requires programming knowledge

Choose Emergent if:

You want to build an app quickly.
You don't know how to code yet.
You want to test an idea or create a prototype.

Choose Android Studio if:

You want to become an Android developer.
You want complete control over your app.
You plan to publish and maintain professional-quality Android apps.

What I'd recommend for you

Based on what you've told me previously—that you're just starting app development and want to build your first apps—I would use both:

Emergent to quickly create working apps and learn how apps are structured.
Android Studio to understand the code, customize features, fix bugs, and eventually build apps independently.

That way, you get fast results and develop real development skills over time.

If your goal is to earn money by building Android apps, learning Android Studio (and Kotlin) is a worthwhile investment. Emergent can speed up the process, but Android Studio remains the standard development environment used by professional Android developers.

Do you know about about the website emergent

Biswajit Porel — Mon, 03 Aug 2026 17:55:09 +0000

Yes, I know about Emergent.

It's an AI-powered app and website builder where you describe your idea in plain English, and the platform generates much of the application for you. It can build:

Android apps
iOS apps
Web apps
Websites
Dashboards
Full-stack applications with backend logic, authentication, and databases (Emergent)

Since I remember you wanted to build a calculator app first, Emergent is actually a good choice if you want to create apps without writing every line of code.

Here's how we could work together:

You tell me your app idea.
I help you write a detailed prompt for Emergent.
You paste the prompt into Emergent.
If the generated app has bugs or missing features, I help you improve the prompt or fix the code.

For example, instead of a simple prompt like:

"Build a calculator app"

I'd help you write something much more detailed, such as:

"Create a modern Android calculator app using Material Design. Include addition, subtraction, multiplication, division, percentage, decimal support, clear and delete buttons, responsive layout for phones, dark mode, input validation, and smooth button animations."

This usually leads to much better results.

So yes—I can act as your development partner while you use Emergent. I can help with:

Designing the app
Writing high-quality prompts
Debugging generated code
Adding new features
Preparing the app for publishing

We can build apps together even if you have little or no programming experience, while I also explain what's happening so you gradually learn app development instead of only relying on AI.