Sunday, January 21, 2018

android kotlin - For loop array example

MainActivity.kt

package com.cfsuman.kotlinexamples

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.widget.Button
import android.widget.TextView


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.text_view)
        val button = findViewById<Button>(R.id.button);
        val button2 = findViewById<Button>(R.id.button2);

        // Array of string
        var colors = arrayOf("Red","Green","Yellow","Magenta","Pink","Black")


        // For loop example, array items
        button.setOnClickListener{
            textView.text = "For loop through array items\n\n"

            // Iterate array without index property
            for (item in colors){
                textView.text = textView.text.toString() + item + "\n"
            }
        }


        // For loop example, array items with index property
        button2.setOnClickListener{
            textView.text = "For loop through array items using index property\n\n"

            // Iterate array without index property
            for (index in colors.indices){
                textView.text = textView.text.toString() + colors[index] + "\n"
            }
        }
    }
}
activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/root_layout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="16dp"
    >
    <Button
        android:id="@+id/button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Loop array items"
        />
    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Loop array items using index"
        />
    <TextView
        android:id="@+id/text_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text=""
        android:textSize="18sp"
        android:textStyle="bold"
        android:textColor="#ff191d"
        android:layout_marginTop="20dp"
        />
</LinearLayout>