If you are looking to learn about pointer in C/C++. Here is the right place for you. Understanding the pointer can be confusing at first time, but you will get the hang of it. I will provide some illustrations and examples to get better a picture about a pointer. There are many other pointers available, they are called Smart Pointers, but for the interest of this article I will be discussing the basic Pointer in C++.

What is a Pointer?

As the name suggests, basically something that points at something. This is pretty much what pointer in C++ does.

Let me describe this in a technical term. A pointer is a variable of a type(int, double, boolean, Array, etc) which holds the address of another variable of a same type, and some times the pointer can be pointed to NULL. Not only pointer has access to the address, and also value of the pointed variable as well. …


If you are looking to learn about IntentService and How to implement it in your app. This is the right place for you. I will be discussing IntentService, how it works, and how to implement in an Android using Kotlin language. General knowledge about Service in Android will be helpful to understand this concept.

A Service is an android component that performs long-running process in the background, and Service does not have a UI component associated with it like an activity. By default, it runs on UI thread or Main thread. It also has lifecycles like an Activity but much simpler. If you start a service, it's your responsible to stop the service, otherwise it will be keep running in the background and draining the phone battery. …


In this article I will be discussing Android Activity launch modes, why we need launch mode, what are the different types of launch modes available, and how they work. Before we dive into that I would like to introduce some topic we often use in this tutorial. Task and Back Stack. In this context Task means collections of activities in an app, and Back Stack means as the name suggest is a stack which does only two operation push/pop in “last in, last out” fashion. An example of Back Stack as follows :

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An illustration of Back Stack.

In an android application, it may have multiple task within the applications, and each task has a back stack which holds the activities in LIFO manner. The activities are pushed based on order the user opened them. For example, lets say we have three activities in an application, lets call it Activity A, B, and C. When the app launches the Activity A will open, then it will be pushed into the back stack, from Activity A the user opens the Activity B, then it will be pushed into the back stack, and finally from the Activity B the user opens the Activity C, then it will be pushed into the back stack. Now the back stack will look like the image above. If the user decided to go back to the Activity B from the Activity C, by pressing the back button. The Activity C will be popped from the stack by calling it finish (Destroyed). Now the stack will look like this…

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