---
title: "Best Kotlin tips for Android application development solutions"  
description: "With inheritx, you don’t run the risk of goof-ups and errors. We have been in business for 6 years and have arguably built the best client portfolio m"  
author: "Inheritx Solutions"  
published: 2018-03-28  
updated: 2018-03-28  
canonical: https://www.mindstick.com/blog/11706/best-kotlin-tips-for-android-application-development-solutions  
category: "android"  
tags: ["android", "android activity", "android sdk", "android games"]  
reading_time: 3 minutes  

---

# Best Kotlin tips for Android application development solutions

Take a look at some of the most useful kotlin tips for developing [Android apps](https://www.mindstick.com/articles/12218/digital-appearance-android-apps-for-banking-sector). Before reading this, it is [required](https://www.mindstick.com/forum/160269/what-is-required-data-annotation-how-does-it-affect-model-validation) you have a good [knowledge](https://www.mindstick.com/forum/156160/what-is-google-knowledge-graph) of kotlin, [experience](https://www.mindstick.com/articles/12276/how-timely-order-deliveries-can-improve-customer-experience) in working with Android SDK. The Android [Application development](https://www.mindstick.com/articles/65303/8-benefits-of-android-application-development-for-online-business) [service providers](https://www.mindstick.com/articles/13099/the-importance-of-machine-learning-service-providers) must also be familiar with the Kotlin plugin and using kotlin with [Android studio](https://www.mindstick.com/blog/10942/android-studio-vs-eclipse). \
\
![Best Kotlin tips for Android application development solutions](https://www.mindstick.com/blogs/e7503bb2-fb35-4ff5-b15e-7734ec41441a/images/c53bc932-4f82-4c14-a8e2-1d7dced005c9.png)\

Without further ado lets jump to initial kotlin tips for Android

Lazy loading \

Lazy loading is extremely useful as it results in faster startup time. When the user opens the app, it opens up immediately without the user having to wait.

For example when creating a shopping app, you can have the actual purchasing API be lazy loaded.

val purchasingApi: PurchasingApi by lazy {

val retrofit: Retrofit = Retrofit.Builder()

.baseUrl(API_URL)

.addConverterFactory(MoshiConverterFactory.create())

.build()

retrofit.create(PurchasingApi::class.java)

}

It is also a good way to encapsulate initialization logic \

// bounds is created as soon as the first call to bounds is made \

val bounds: RectF by lazy {

RectF(0f, 0f, width.toFloat(), height.toFloat())

}

Lambdas \

Lambas reduce the line of code in a source file. \

An on-click listener looks something like this

button.setOnClickListener { view ->

startDetailActivity()

}

It even works with return values. \

toolbar.setOnLongClickListener {

showContextMenu()

true

}

Collection filtering \

One comes across collection filtering while working with API. The collection filtering in Kotlin adds more clarity and makes code more Succint. Something like this \

val users = api.getUsers() \

// we only want to show the active users in one list

val activeUsersNames = items.filter {

it.active // the "it" variable is the parameter for single parameter lamdba functions

}

adapter.setUsers(activeUsers)

Custom Getters/setters \

By using custom Getters/setters, the access can be simplified.

Something like this

@ParseClassName("Book")

class Book : ParseObject() {

// getString() and put() are methods that come from ParseObject

var name: String

get() = getString("name")

set(value) = put("name", value)

var author: String

get() = getString("author")

set(value) = put("author", value)

}

Global constants

When the scope needs to be global, kotlin provides best ways to do so without having to go through a constant class.

package com.savvyapps.example

import android.support.annotation.StringDef

// Note that this is not a class, or an object

const val PRESENTATION_MODE_PRESENTING = "presenting"

const val PRESENTATION_MODE_EDITING = "editing"

They can be used as constants anywhere in the project

import com.savvyapps.example.PRESENTATION_MODE_EDITING

val currentPresentationMode = PRESENTATION_MODE_EDITING

Leveraging let

Leveraging let allows Android App development providers execute a block if the value of the object is not null. For example this is how it looks like in Java.

if (currentUser != null) {

text.setText(currentUser.name)

}

And in Kotlin, it looks something like this.

user?.let {

println(it.name)

}

Extensions

Adding extensions is an intermediate kotlin tip. Using extensions, you can add to the functionality of a class without having to Inherit from it. With the extensions, you can accomplish this easily.

fun Activity.hideKeyboard(): Boolean {

val view = currentFocus

view?.let {

val inputMethodManager = getSystemService(Context.INPUT_METHOD_SERVICE)

as InputMethodManager

return inputMethodManager.hideSoftInputFromWindow(view.windowToken,

InputMethodManager.HIDE_NOT_ALWAYS)

}

return false

}

Data classes

Data classes simplify classes, adding copy(), equals(), and toString(),hashCode(),methods automatically.

For example, take a look at this data class.

data class User(val name: String, val age: Int)

With inheritx, you don’t run the risk of goof-ups and errors. We have been in business for 6 years and have arguably built the best client portfolio [mobile app development](https://www.mindstick.com/services/mobile-app-development) and services.

We have a handpicked team of developers, designers, who work across Android, iOS and phone gap platforms. For more tips on kotlin, contact us now.

---

Original Source: https://www.mindstick.com/blog/11706/best-kotlin-tips-for-android-application-development-solutions

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