Dart Programming

Dart Hello World

Dart is a Google-developed static programming language. It allows for client-side and server-side application development. As per the GitHub adoption index, it has become the most widely used programming language because it incorporates the flutter toolkit. However, the Flutter Framework is commonly utilized in developing Android applications, iOS applications, IoT (Internet of Things), and online applications. Dart has a high syntactic and semantic similarity to JavaScript, Java, CPP, and python. It is a vibrant object-oriented language with lexical scope and closure. Dart was released in 2011, but it gained prominence after 2015 with the release of Dart 2.0.

In this article, we will look at the basic representation of Dart syntax and how to print hello world in the dart programming language. The fundamental framework of Dart programming will be demonstrated here.

What is Hello World in Dart in Ubuntu 20.04?

A “Hello, World!” script is a computer program that shows or outputs the statement “Hello, World!”. This practice program demonstrates the fundamental structure of a computer language. When beginners are taught a new language, they frequently write a “Hello, World!” program as their first program. It’s mostly used as a dry run to ensure that a programming language is appropriately installed. Because setting a programming language is a time-consuming and complex procedure, a simple program such as “Hello, World!” is often used as a first-run evaluation of a new toolkit.

How to Print ‘Hello World’ in Dart in Ubuntu 20.04?

The Dart programming language uses “Hello, World!” to print in the various program in different ways below. First, we need to ensure that the Dart programming language is installed on our Ubuntu 20.04 machine.

Then, use any text editor in Ubuntu 20.04 to write and save the program file. The program file of Dart programming language is saved in the extension “.dart”. Open the terminal and compile the code like this “dart file_name.dart”. This command will compile your code in dart programming language and displays the output after compilation.

Example # 1: Print ‘Hello World’ in Dart in Ubuntu 20.04

The program to print the ‘hello world’ is very simple in a dart programming language. Let’s have a program implementation demonstration below.

We have the void main function in the initial step. This function’s return type is void. We need to explain these keywords void and main for a dart programming language. The “void” is the keyword that indicates that nothing will be returned from this function to the compiler. The “main” keyword from the program begins. Within the main function, we have a print function used to display the message on the screen. The message can be structured as a string, expression, or another object. Then, the “hello world” is passed inside the print function brackets displayed on the screen.

Here, the code is saved in a dart file “hello. dart” and compiled the program by opening the terminal shell of Ubuntu 20.04. Thus, Hello World is printed in a prompt shell.

Example # 2: Print ‘Hello World’ by String Interpolation in Dart in Ubuntu 20.04

The preceding program has the general way of printing the ‘Hello World’ in quite an advanced manner. We are using string interpolation syntax in a dart programming language as you are familiar with the string interpolation syntax in other computer languages. The string interpolation representation in a dart programming language is like this: ${expression}.

Inside the main function of the above program. We have used a string keyword which is a data type. This String keyword is used here for string declaration. Here, we have declared two strings as “str1” and “str2”. The string “str1” is initialized with the string “Hello,” and the string “Str2” is initialized with the string value “World”. Calling the print function within the main function. The print function has a message, and along with the message, we used string interpolation representation for the above-specified strings as ${str1} and ${str2}. The dollar sign “$” takes the strings inside the parentheses and will display the corresponding values each string has in it.

The message used string interpolation representation inside the print function, with the following outcome. Note that the string interpolation syntax displays the values stored in the string.

Example # 3: Print ‘Hello World’ by Function Definition in Dart in Ubuntu 20.04

We can also print the “Hello World” in a dart programming language with the function definition. This way is quite an advanced technique rather than the above techniques. Functions also could return the value together with the control to the caller. Such functions are referred to as returning functions.

We have called the dart’s built-in print function within the main function parentheses. We have another function invoked inside our print function called “fun”. This function is defined outside the main. We have a function as “fun” outside the main function, which has a string return type. The function has the return statement of a string as we have used the return keyword with the string statement. Note that each function can only have one return statement. The return is the last statement of every function, which is optional.

Thus, the returning function has returned the string of “Hello World” as printed as the output in the command shell.

Example # 4: Print Five Times ‘Hello World’ in Dart in Ubuntu 20.04

We can print hello world as many times as possible in the dart program using the loop. Here in the example, we use the Do while loop, which will print “Hello World” five times.

The Dart Do-While loop expression is the same as the while loop statement, other than the expression in the loop is run first, followed by a check of the condition.

There inside the main of the program, the dart variable is represented with the “var” keyword and defined by assigning a name “n,” which is initialized by the value zero. Then, the loop block “do” is used, and within the “do” block, we have a print statement of “Hello World”.

Next, we have an incremental representation of the variable “n”. This will increment up to the given value in the while loop block. There comes a “while” block where the condition is given that variable “n” should be less than a value “5”.

The “Hello World” statement is printed five times, as you can see in the below shell screen of Ubuntu 20.04.

Conclusion

Finally! we learned how to use the dart command to run a basic hello world program written in the Dart programming language. We have covered four different ways to print the “Hello World” statement in the dart program. Firstly, we have explained the simplest and easiest way, then moved to a quite advanced way. You can promptly print a “Hello World” in the dart programming language by using one of these methods.

About the author

Saeed Raza

Hello geeks! I am here to guide you about your tech-related issues. My expertise revolves around Linux, Databases & Programming. Additionally, I am practicing law in Pakistan. Cheers to all of you.