Interview Question & Answer – 5

By | October 3, 2018

Question Alice and Bob each created one problem for our company. A reviewer rates the two challenges, awarding points on a scale from to for three categories: problem clarity, originality, and difficulty. We define the rating for Alice’s challenge to be the triplet , and the rating for Bob’s challenge to be the triplet . Your task is… Read More »

Interview Question & Answer – 4

By | October 2, 2018

Question Lilah has a string, , of lowercase English letters that she repeated infinitely many times. Given an integer, , find and print the number of letter a’s in the first letters of Lilah’s infinite string. For example, if the string and , the substring we consider is , the first characters of her infinite string. There are… Read More »

Simple Interview Question and Answer – 1

By | September 28, 2018

Question John works at a clothing store. He has a large pile of socks that he must pair by color for sale. Given an array of integers representing the color of each sock, determine how many pairs of socks with matching colors there are. For example, there are socks with colors . There is one pair of color… Read More »

SQlite Database Operations in Flutter

By | September 27, 2018

SQFlite is a Flutter library for doing local Database Operations. You can download it from here. To Integrate SQFlite library in your project In your flutter project add the dependency: You can download the sample project from here. Here is a sample DB Utility file. DBHelper.dart

How to do Unit Test of functions and Widgets in Flutter?

By | September 24, 2018

Lets see how we can test Flutter Apps. It would be easy if we continue from the previous example…   Start unit Testing We will create a test file named ‘widget_test.dart’ inside the ‘test’ folder. To test Widgets, we will use the ‘testWidgets’ function. Lets see how it will look like… The test function in MyHomePage will look… Read More »

Things to Know About Mobile UX

By | August 30, 2018

Mobile user experience is not only related to design something to use on the mobile devices. It is a process that requires brainstorming, research and development to find out how you can better consider the UX and apply it in your UI. Keep in mind that the number of mobile internet users is increasing day by day. So,… Read More »

Project Treble – Android Version Fragmentation Solved

By | August 18, 2018

Solved Yes, a longtime problem with Android has been solved. Yes, version fragmentation problem. Version fragmentation is often Android from different manufacturers had been stuck on different versions which makes it difficult for developers to support all variety of devices. Hopefully the problem is going to be solved. From Google’s perspective, an OS rollout is actually a three-stage… Read More »

How to listen to events from react native?

By | August 14, 2018

Hi friends, This is essentially a continuation of this post http://www.coderzheaven.com/2018/08/10/how-to-create-a-custom-native-imageview-in-android-for-reactnative/ Now we will listen to a click event from the image we just created. For that we have to add the ClickListener to the image in Android. Add below methods to the java class On the React Native Side The whole java class will look like this.

How to extend styles in React-Native?

By | August 12, 2018

We will create different styles to style different components, correct? And most of them will have duplicate elements, correct? What are the disadvantages of this problem? You will clutter your file with duplicate lines of code. It will increase the file size and increase the application size. Not very efficient way of coding. Limited reusability. How to fix… Read More »

How to create a custom native ImageView/View in Android or iOS for ReactNative?

By | August 10, 2018

Many times we need custom components from native. Here is a simple example on how to create a custom imageview in Android for react native. First we will start with the Android Version Android Create a class that extends SimpleViewManager. Write a setSrc method which accepts the source url from React Native. Implement ‘createViewInstance’ method in which you… Read More »

How to Monitor network requests in a React Native/React Application?

By | August 9, 2018

So how do we normally monitor all the operations in a react native applications. All the networks, redux state etc. So you will need a plugin/package for this. Its called Reactotron. Here is the github page for Reactotron. What is Reactotron? A macOS, Windows, and Linux app for inspecting your React JS and React Native apps. Use it… Read More »

Awesome React Native Image Caching Libraries

By | August 4, 2018

Image Loading and caching had been a little bit pain in react native. In-fact react native didn’t had native support for caching. But after the recent release, there is now support for caching in iOS only. Still not for Android. You can read more about this from here https://facebook.github.io/react-native/docs/images.html#cache-control-ios-only Now these are the variety of options available. default:… Read More »

All About React Native Animation

By | July 25, 2018

Animations are achieved in React Native using the Animation API. Below are the methods Animated.timing() — Maps time range to easing value. Animated.decay() — starts with an initial velocity and gradually slows to a stop. Animated.spring() — Simple single-spring physics model (Based on Rebound and Origami). Tracks velocity state to create fluid motions as the toValue updates, and can be chained together. Here we… Read More »

Top 10 most downloaded and used mobile apps

By | July 23, 2018

Studies show that we spend more time with our mobile devices every day, either working or enjoying our leisure time. And we use apps in these devices . But what are the ones that we use the most? Sensor Tower is a company dedicated to the marketing of mobile applications, which periodically publishes a report that collects the… Read More »

8 things you need to know before becoming a blockchain developer

By | July 20, 2018

The blockchain is one of the fastest-growing markets in the entire IT industry. According to the report, the global blockchain technology market is predicted to reach $2.3 billion by 2021, creating a big demand for more engineers and software developers. It obviously represents a colossal career potential for talented blockchain specialists. An average software developer in the US… Read More »

Free Daily News App

By | July 18, 2018

Download our free news app and get instant news from popular news channels instantly. Get the app from here… https://play.google.com/store/apps/details?id=app.mobile.daily_news          Please download and leave your valuable feedback as well. Why you will download this app? Fast and efficient. Incorporates news from all famous news channels. Consumes minimal battery. No intruding ads or notifications. Completely… Read More »

How Image Loading Libraries work in Android?

By | July 14, 2018

In this article, Lets find out how the image loading libraries like Picasso, Glide and Fresco works. We know that images are the one which takes most of the space in our application either in App size or the memory at runtime. Also using large number of images often kicks off Garbage Collection (GC) Events. The more number… Read More »

How to show a Snackbar in Flutter? iOS and Android.

By | May 20, 2018

Here is a simple example where the user clicks a button to show a Snackbar. We know that there is no inbuilt snackbar for iOS. But Flutter makes it easy to do without any custom native code. You can see a Demo video here. Here we use two main elements Scaffold Snackbar The Scaffold Widget from the material… Read More »

How to encrypt and decrypt an audio file in Android?

By | May 8, 2018

Here is a simple example to encrypt and decrypt a audio file in Android. We will directly go to the implementation part. Demo Video You can check the demo video here. Download Library You can download the simple library from here. Aim Download an audio file from internet. Encrypt and save the encrypted file in Disk, so that… Read More »