Learn Kotlin and build 2 basic android apps from scratch

Github repo for course files

Every language has basic structure of variables and constants to store data. Variable to store data that can change and constants to have data that is fixed. It is recommend that we should use constants as much as possible

Numbers are very easy to handle in kotlin. Kotlin automatically determines that the value that is coming is integer of double.

In any programming language, you will have to deal up with strings most of the time. Kotlin takes care of that too. on top of that, all java functions can be imported to handle strings

Nulls are notoriously famous for making problems. Kotlin handles null nicely. It gives us an extra check for nulls by providing special datatypes for null.

So far, we have been using REPL as it is very fast in getting started but now, it is time to move at file and write some persistent code.

Most basic condition checker in any programming language is if and else, and so is in the Kotlin.Syntax of IF and Else will look very familiar if you have worked in any programming language previously

Now, to get more confidence with If and Else, we will learn about ODD and EVEN finder. It is one of the most common exercise that we do to master if and else

Now, let's design a simple grade system, where students with above 90% will get A and passing marks is 40. Also there are in between grades. WE can do this easily with WHEN

Again, one more exercise to find out biggest number of all. This is again being solved by If and Else. These exercises will help you to master logic building

WHEN is like a substitute of switch and case in many other languages. Instead of going too deep into nested if else, we can use WHEN and program it for various cases

if, else syntax and when are great to determine any result. But you can also store the result output of that conditional check in a variable or constant. We will look at this feature in this video

Now moving towards the advance datatypes. Array is the most used advance datatype. Make sure that always keep in mind that array starts with 0

Array list is another data type in Kotlin. The difference between array and array list is that Array cannot be changed once you have defined it on runtime. While array list is mutable and has options like add and remove.

Loops are most basic way to iterate any task. In this video will look at most basic and most commonly used loop, For loop. Syntax of for loops is simple, a variable loops through a collection.

While loop is a condition based check and run loop. This loop will only run when the condition is satisfied. Kind of if else is integrated with loops

There are 2 loop control statements. Break and continue. Break helps us to break the complete flow of loop while, on the other hand, continue just skips those iterations that matches the condition

Functions are the most basic building block in Kotlin. These functions will help you to write better code. in the android development also, functions are must to have tools in belt

One of the most impressive thing about Kotlin is that it works seamlessly with Java. All java packages can be imported in Kotlin and can be used. In this video, we will learn to import java in Kotlin

Now, this is again a fun exercise. Let just that you have an email list and you want to put a filter on that email list and select only a particular type of values. Same will be demonstrated in this video

The most basic fundamentals of Object oriented programming is Classes and Objects. In this video we will learn about Classes and objects in Kotlin

Methods are just like functions or I would like to say exactly are function. But they are just declared inside the classes and are termed as methods

Constructor are pre defined methods that are called once and as soon as the object is created. This is one the very good point to declare defaults in objects

Many times,while defining the objects, we want that object should have some predefined or default values. Once the default value is assigned, that value becomes optional to pass for the user

Inheritance is the property where we can use the functions defined in other classes without copying it into our file/class. For the inheritance to happen, make sure that your class is open

Abstract class and abstract method helps to put rules on classes that will inherit our class. We can mention that whoever is going to inherit this class, XYZ method is compulsory to declare.

Interface is just like defining rules. You want to mention that this class order that there should be these properties defined and these methods to be defined, if you want to use this class

Many times we just want to store data in class. Data like API key or URL info or Tokens, for that we can create a special data class that just holds our data

This is a great example of restricting our usage. In this case we will learn that seats should be only of three types in this case.

When we create object in classes, we can access them and can assign values to them. Getters and setters allows us to put restrictions and checks on this assignment of values as well as access to those values

Learn about the access modifies like making a class public, private or protected. These all behave differently and sometimes are good to have

Create a simple hello world application in Android studio 3. We will be setting up few kotlin extensions and will make a simple toast on press of a button

Now, we will make another app in Android with Kotlin. In this video we will set Android calculator design. 

In this video we will write code to run our calculator. Goal is really simple, 

1. Take input from user and parse it as integer

2. Run a function on tap of a button

3. Display the result

Thanks for taking the class, have a look at more igneus technologies courses at Udemy