android kotlin - Array example

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 button = findViewById<Button>(R.id.button)


        // make textview content scrollable
        textView.movementMethod = ScrollingMovementMethod()


        // Button click listener
        button.setOnClickListener {
            // Initialize a new array with values
            val myArray = arrayOf("Rose",1,"Pink",9.0, 8.5F)

            // Initialize a string array with default value
            var myStringArray = Array(3){""}

            // Initialize a string array with default value and type
            var myStringArray2 = Array<String>(3){""}

            // Initialize a new int array with default value
            val myIntArray =  Array(5){6}

            // Initialize a new Int array with values
            var myIntArray2:IntArray = intArrayOf(1,2,3,4)

            // Initialize a double array with default value
            var myDoubleArray = Array<Double>(3){10.0}

            // Initialize a float array with default value
            var myFloatArray = Array<Float>(2){10.0F}


            // Display the first array elements in text view
            textView.text = "First Array elements\n"

            // Loop through the first array elements
            for (element in myArray){
                textView.text = textView.text.toString() + element + ", "
            }


            // Display the int array elements in text view
            textView.text = textView.text.toString() +
                    "\n\nInt array elements\n"

            // Loop through the first array elements
            for (element in myIntArray){
                textView.text = textView.text.toString() + element + ", "
            }


            // Updating a default value of integer array
            myIntArray[2] = 10

            // After update displaying the int array elements in text view
            textView.text = textView.text.toString() +
                    "\n\nAfter updating, int array elements\n"

            // Loop through the first array elements
            for (element in myIntArray){
                textView.text = textView.text.toString() + element + ", "
            }


            // Sum of int array elements
            textView.text = textView.text.toString() +
                    "\n\nSum of int array elements is " +
                    ": ${myIntArray.sum()}\n"


            // Average of int array elements
            textView.text = textView.text.toString() +
                    "\n\nAverage of int array elements is " +
                    ": ${myIntArray.average()}\n"
        }
    }
}

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/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Array"
        android:textAllCaps="false"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <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/button" />

</androidx.constraintlayout.widget.ConstraintLayout>

More android examples