Jetpack Compose — Basic Composable

import androidx.compose.foundation.layout.*
import androidx.compose.material3.*
import androidx.compose.runtime.*
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp

@Composable
fun Greeting(name: String, modifier: Modifier = Modifier) {
    Column(modifier = modifier.padding(16.dp)) {
        Text(
            text = "Hello, $name!",
            style = MaterialTheme.typography.headlineMedium
        )
        Text("Welcome to Compose.", style = MaterialTheme.typography.bodyMedium)
    }
}

@Composable
fun Counter() {
    var count by remember { mutableStateOf(0) }      // local state
    Column {
        Text("Count: $count")
        Button(onClick = { count++ }) {
            Text("Increment")
        }
    }
}