Learn Flutter & Dart like a pro — Dart Basics
In the last article we installed Flutter & Dart and improved our setup with numerous Visual Studio Code Extensions. Now let’s take a look at the basics of Dart and learn the syntax of Dart.
Note: This series is not intended to teach you programming from scratch. You should already have an understanding of programming and now want to learn Dart & Flutter.
A simple Dart program
Now let’s look at the simplest dart program, a typical “Hello, World!” program. Every Dart program starts with a main function, which is later executed first.
Great! But this doesn’t help yet, because there is nothing between the {} that can be executed.
With the function print you can easily type something into the console.
As you can see, we wrote ‘ ’ inside of the brackets. These are there to represent a string. But you can also write strings with “ ” in Dart.
You can also see that there is a semicolon after the print. This is always needed after a statement in Dart. Complex statements, such as for-loops or if-queries, do not need a semicolon, but more about that later.
Very good, now we know how a Dart program is basically structured. Now let’s take a closer look at the individual topics.
Comments
You write a single line comment like this:
You can also write your comments over several lines:
Great! But there is another way to write comments, which is very useful for large comments:
Everything that is between the /* and the */ will be commented.
However, there are not only normal Comments in Dart. There are also Documentation Comments. You can write them with ///:
And over several lines:
Arithmetic Operations
To be able to perform calculations, we need arithmetic operations. These are, as in real mathematics, between the numbers.
- Add: +
- Subtract: -
- Multiply: *
- Divide: /
Okay, that was very simple. But Dart also offers Math functions, which can be very helpful. To do this you import the library dart:math:
(Now you have already learned how imports work. We will discuss this in more detail later).
Now you can call some functions like this:
min: Find the smallest value of something. Example:min(5, 10);will be 5.max: Find out the largest value of something. Example:max(5, 10);will be 10.sqrt: Gives you the square root of a number. Example:sqrt(3)is 1.732050808.
There are other functions like sin for sine functions or cos for cosine functions.
There is a lot more to say about the dart:math library. To learn more about it, you can check out the document: https://api.dart.dev/stable/2.16.1/dart-math/dart-math-library.html
Conclusion
That’s it for today. You have learned how a simple dart program is built and something about comments. You also know how to use mathematical functions.
A little exercise for you: Try to combine the functions used above.
In the next article of this series, we will deal with the use of variables.
Thanks for reading, have a nice day!
