ajaypro

Moving to last element in array and moving towards left till we reach an even element

int[] arr = {1, 2, 3, 4, 5};
int i = arr.length -1;

while(i>=0 && arr[i] % 2 == 1)
  i--;
  
------------------------------------------------

ajaypro

UseCase: If we want to show in a textview "Model : BMW" 
model - static data 
BMW - dynamic data, If your doing a n/w call and in your model you have a model attribute for vehcile object, below is one of approach.
-------
define this in your strings.xml 

<string name="display_model">Model %s</string>

* In case you have a data object vehicle as a livedata  then you do something like this in your Viewmodel
* displayModel is a variable that will be used by data binding to show in your layout

ajaypro

consider you want to have an EditText for taking only alpha numeric values as input. 

<android.support.v7.widget.AppCompatEditText
        android:id="@+id/newDeliverable"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:digits="1234567890 abcdefghijklmnopqrstuvwxyz"
        android:hint="@string/hint_add_new_deliverable"

ajaypro

// Result is a superpowered enum that can be Success or Failure
// and the basis for a railway junction
sealed class Result<T>
data class Success<T>(val value: T): Result<T>()
data class Failure<T>(val errorMessage: String): Result<T>()

// Composition: apply a function f to Success results
infix fun <T,U> Result<T>.then(f: (T) -> Result<U>) = 
    when (this) {
        is Success -> f(this.value)

ajaypro

When we have to define a variable that will be later initialized as done below. 

fun main() {
   
    var lazyValue: Int? = null
   
    fun getlazyValue(): Int?{
    if(lazyValue == null){
        lazyValue = 45
        

ajaypro

Labledreturn from function

fun main(args: Array<String>) {
   foo(listOf(1,0,3,4))
}
 
fun foo(ints: List<Int>) {
    ints.forEach inner@ {
        if (it == 0) return@inner
 

ajaypro

/**
 * Usage of infix functio, Pair<String, Int> and multiple return types 
 */

fun main() {
    
    /** you can assign the variables of the Pair to another variable and use those 
     * variables like below 
    */
    

ajaypro

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

ajaypro

@Database(entities = {objects.ChecklistItem.class, OfflineData.class}, version = 4, exportSchema = false)
@TypeConverters({DateConverter.class, GeopointsConverter.class})
public abstract class   DbChecklist extends RoomDatabase {

    private static final Object LOCK = new Object();
    private static final String DATABASE_NAME = "****.db";
    private static DbChecklist sInstance;

    public static DbChecklist getsInstance(Context context) {
        //to make sure that Singleton Pattern is followed

ajaypro

package io.github.project_travel_mate.destinations.offlinedata;

import android.arch.persistence.room.ColumnInfo;
import android.arch.persistence.room.Entity;
import android.arch.persistence.room.PrimaryKey;
import android.arch.persistence.room.TypeConverters;
import android.content.Context;

import org.osmdroid.util.GeoPoint;