MainActivity.kt
package com.cfsuman.kotlintutorials
import android.os.Bundle
import android.text.method.ScrollingMovementMethod
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)
// get the widgets reference from XML layout
val textView = findViewById<TextView>(R.id.textView)
val btnList = findViewById<Button>(R.id.btnList)
val btnSort = findViewById<Button>(R.id.btnSort)
val btnSortDescending = findViewById<Button>(
R.id.btnSortDescending)
// make textview content scrollable
textView.movementMethod = ScrollingMovementMethod()
btnList.setOnClickListener {
val list = mutableListOf('x','c','z','a',
'y','p','b','d','u')
textView.text = "List :\n"
// Iterate through the list
list.forEach {
textView.append("$it, ")
}
}
btnSort.setOnClickListener {
val list = mutableListOf('x','c','z','a',
'y','p','b','d','u')
list.sort()
textView.text = "List sorted :\n"
// Iterate through the list
list.forEach {
textView.append("$it, ")
}
}
btnSortDescending.setOnClickListener {
val list = mutableListOf('x','c','z','a',
'y','p','b','d','u')
// return Unit
list.sortDescending()
textView.text = "List sorted descending :\n"
// Iterate through the list
list.forEach {
textView.append("$it, ")
}
}
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
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"
android:background="#F8F8F8"
android:padding="24dp">
<Button
android:id="@+id/btnList"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="List"
android:textAllCaps="false"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Button
android:id="@+id/btnSort"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:text="Sort"
android:textAllCaps="false"
app:layout_constraintBottom_toBottomOf="@+id/btnList"
app:layout_constraintStart_toEndOf="@+id/btnList" />
<Button
android:id="@+id/btnSortDescending"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:text="Sort Descending"
android:textAllCaps="false"
app:layout_constraintBottom_toBottomOf="@+id/btnSort"
app:layout_constraintStart_toEndOf="@+id/btnSort" />
<TextView
android:id="@+id/textView"
android:layout_width="0dp"
android:layout_height="0dp"
android:layout_marginTop="16dp"
android:fontFamily="sans-serif"
android:textSize="24sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/btnList" />
</androidx.constraintlayout.widget.ConstraintLayout>



- kotlin syntax - List sortBy and sortByDescending
- kotlin syntax - List sorted and sortedDescending
- kotlin syntax - List sort by multiple fields
- kotlin syntax - Sort list using comparator
- kotlin syntax - List filter not null
- kotlin syntax - List of not null
- kotlin syntax - Distinct
- kotlin syntax - distinctBy
- kotlin syntax - distinctBy multiple fields
- kotlin syntax - maxBy and maxWith