RADIO GROUP AND RADIO BUTTON

E:\android\MyApplication\app\src\main\res\layout\activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="#FF5722"
        android:textSize="30sp"
        android:textStyle="bold"
        android:textAllCaps="true"
        android:padding="10dp"
        android:layout_margin="10dp"
        android:gravity="center"
        android:layout_gravity="center"
        android:id="@+id/tv1"
        />


    <RadioGroup
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:id="@+id/rg">
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/r1"
            android:text="Male"></RadioButton>
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/r2"
            android:text="Female"></RadioButton>
    </RadioGroup>

</LinearLayout>

E:\android\MyApplication\app\src\main\java\com\example\myapplication\MainActivity.kt

package com.example.myapplication

import android.os.Bundle
import android.widget.RadioButton
import android.widget.RadioGroup
import android.widget.TextView
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity

class MainActivity : AppCompatActivity() {

    private lateinit var tv: TextView
    private lateinit var radiogroup: RadioGroup
    private lateinit var r1: RadioButton
    private lateinit var r2: RadioButton

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Enable edge-to-edge content
        enableEdgeToEdge()

        // Find views by ID
        tv = findViewById(R.id.tv1)
        radiogroup = findViewById(R.id.rg)
        r1 = findViewById(R.id.r1)
        r2 = findViewById(R.id.r2)

        // Set a listener for the RadioGroup
        radiogroup.setOnCheckedChangeListener { group, checkedId ->
            when (checkedId) {
                R.id.r1 -> tv.text = "MALE"
                R.id.r2 -> tv.text = "FEMALE"
            }
        }
    }
}

Output: