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);
val button3 = findViewById<Button>(R.id.button3);
val button4 = findViewById<Button>(R.id.button4);
// For loop example, simple range
button.setOnClickListener{
textView.text = "For loop 1 to 10 \n"
// Loop through the range
for (i in 1..10){
textView.text = textView.text.toString() +" " + i + "\n"
}
}
// For loop down to example
button2.setOnClickListener{
textView.text = "For loop 10 down to 1 \n"
for(i in 10 downTo 1){
textView.text = textView.text.toString() + " " + i + "\n"
}
}
// For loop range 1 to 10 and step 2
button3.setOnClickListener{
textView.text = "For loop 1 to 10 and step 2 \n"
for (i in 1..10 step 2){
textView.text = textView.text.toString() + " " + i + "\n"
}
}
// For loop range 10 down to 1 and step 2
button4.setOnClickListener{
textView.text = "For loop 10 down to 1 and step 2 \n"
for (i in 10 downTo 1 step 2){
textView.text = textView.text.toString() + " " + i + "\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="Range 1..10"
/>
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Range 10 down to 1"
/>
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Range 1..10 Step 2"
/>
<Button
android:id="@+id/button4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Range 10..1 Step 2"
/>
<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>




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