Getting Started With Julia Programming Language: With Practical Implementation!

Akshay Gupta — Published On May 15, 2021 and Last Modified On June 8th, 2021

This article was published as a part of the Data Science Blogathon.

Introduction

Hello Readers!!

Walks like python. Runs like C

The above line explains to a ton why I decided to compose this article🤩. I went over Julia some time prior despite the fact that it was in its beginning phases, it was all the while making swells in the mathematical registering space.

Julia is developed by MIT, a high-level language that has a syntax that is beginners friendly as Python and fast as C. This isn’t all, It gives distributed parallel execution, a sophisticated compiler, mathematical precision, and a broad numerical function library.

So in this blog, we are going to learn the basics of Julia Programming language with the help of code snippets. This article covers the basics of Julia, which helps you to give an overview on how to declare variables, how to use functions, and many more.

If you’re interested in Machine Learning in Julia, then checkout Start Machine Leaning With Julia: Top Julia Libraries For Machine Learning🙂

If you’re interested in data visualization in Julia, then checkout Data Visualization In Julia Using Plots.jl: With Practical Implementation😅

Variables And Type

In this section, we will learn variables and their types and how to perform simple mathematical operations using Julia.

Variables

In programming, when we want to store the data we want a container to store it, the name of this container is called variable. When we want to store the data in a variable, we do this by writing the below code:

name = "Akshay"
number = 23
pie_value = 3.141

Here, the name is a string that contains a text value, a number contains an integer and pie_value is a floating number. Unlike C++, we don’t need to specify variable type before the variable name.

Print the variable

If you want to print the value of the variable, we use the print keyword. Check the below code to print the variable value:

>>> print(name)
   Akshay

Mathematical operations

In Julia, many mathematical operations are present which we can perform on variables. For example addition, multiplication, subtraction and many more.

a = 2
b = 3
sum = a + b
difference = a - b
product = a * b
quotient = b / a
power = a^3
modulus = b % a

Check the below image for all the mathematical operations that are available in Julia:

For complete information on mathematical operations check this link

Data Type

In Julia, every variable has its data type. There are many data types in Julia like Float, Int, String. Check the below image for all the data types that are available in Julia:

If we want to determine the type of variable, then we use typeof function:

>>>typeof(0.2)
Float64
>>>typeof(50)
Int64
>>>typeof("Akshay")
String

For more information on variables and their types, check this Link.

Functions

These are the buildings blocks of Julia. All the operations that we perform on variables are carried out with the help of functions. These are also used to perform mathematical operations on variables. In a nutshell, a function is a kind of box that takes the input to perform some operations and then finally return an output. In this section, we will study function in great detail.

Defining functions

In Julia, the function starts with the function keyword and ends with the end.

function plus_two_number(x)
      #perform addition operation
        return x + 2
end

Note: Indentation is a must in Julia. As you can see in the above code in line number 2 and 3. Please note that there are not any fixed number of indentation spaces, but generally, four spaces are preferred.

An inline version of a function

We can also create an inline version of the function

plus_two_number(x) = x+2

Anonymous Functions

We use the lamdas function in Python, similarly, in Julia, we can create anonymous functions using the below code:

plus_two_number = x -> x+2

Void Functions

A function that takes no argument and returns no value is called a void function. Check the below code that doesn’t take any argument and print the Hello message.

function say_hello()
      println("Hello")
      return
end

Note: We can use println function also to print the output value but it adds a new line to the end of the output.

Optional Positional Arguments

We can also take a value from the user and pass it to the function. Check the below code which converts weight(in kg) on Earth to some other value on a different planet

function Weight_calc(weight_Earth, g=9.81)
      return weight_Earth*g/9.81
end

Check the output below:

>>>Weight_calc(60)
60
>>>Weight_calc(60, 3.72)
22.75

For more information on functions, check this link

Data Structures

In this section, we will discuss how we can store data in memory using different data structures. We will discuss vectors, tuples, named tuples, matrices and dictionaries.

Vectors

It is a list of ordered data which is having a common type (example Int, Any or Float) and it is a one-dimensional array. Check the below syntax to create a vector in Julia:

a = [1,2,3,4,5,6,7]
b = [1.2, 3,4,5,6]
c = ["Akshay", "Gupta", "xyz"]

Matrices

It is two-dimensional arrays. Check the below syntax to create a matrice in Julia

Matri_1 = [4,5,7; 8,1,3]

Tuples

It is a fixed size group of variables and may contain a common type of data but it is not compulsory. Once the tuple is created, you can not increase the size. Tuples are created using below syntax:

a = (1,2,3,4,5)
b = 1, 2, 3, 4, 5

So these can be created by using parenthesis or without using them.

Tuple_1 = (1, 2, 3, 4)
a, b, c, d= Tuple_1
>>>print("$a $b $c $d")
1 2 3 4

Named Tuples

They are the same as a tuple with a name identifier for a single value. Check below example for the named tuple:

>>> named_tuple = (a = 1, b = "hello")
(a = 1, b = "hello")
>>>named_tuple[:a]
1

Dictionaries

It is a collection of keys and values. They are unordered which means the order of key is not fixed. Check the below syntax to create a dictionary in Julia using the Dict keyword

Person_1 = Dict("Name" => "Akshay", "Phone" => 83659108, "Pant-size" => 40)
Person_2 = Dict("Name" => "Raju", "Phone" => 75973937, "Pant-size" => 36)
>>>print(Person_1[“Name”])
   Akshay

For more information on data structures in Julia, check this link

Control Flow

In this section of the blog, we will see control statements in Julia. First, we will start with conditional blocks for example if … else and after that, we will see how to perform looping using For and While Loops.

If … else

I hope you must have studied about if else condition in C/C++. So, it uses to make decisions according to certain conditions.

For example, we want an absolute value of a number. It means we if the number that is passed is positive, then we will return the number itself. On the other hand, if it’s negative, then we will return the opposite if a number. Check the below code on how the if-else statements work.

function absolute_value(x)
    if x >= 0
        return x
    else
        return -x
    end
end

Note: You can see if-else block is ended with end, like a function

Check More Than One Condition

If you want to check more than two conditions, then we can use

and (written as &)
or (written as || )

Check the below code on how to use and condition

if 1 < 4 & 3 < 5
    print("Welcome!")
end

For Loops

If we want to iterate over a list of values and perform some operation then we can use it for loop in Julia. Check the below code to print the square of values from 1 to 10.

for j in 1:10
    println(j^2)
end

Output

While Loop

Check the below code of While loop in Julia

function while_loop()
    j=1
    while(j<20)
        println(j)
        j += 1
    end
end

Break

If we want to come out of the loop after a certain condition is met, use a Break keyword. Check the below code on how to use Break in Julia

for j in 1:10
    if j>3
        break
    else
        println(j^2)
    end
end

Continue

Check the below code on how to use the Continue keyword in Julia

for j in 1:20
    if j %2 == 0
        continue
    else
        println(j)
    end
end

For more information on iterators and control flow, check this link

Conclusion

So in this article, we had a great detailed discussion on the Basics of Julia Programming Language. Hope you learn something from this blog and it will turn out best for your project. Thanks for reading and your patience. Good luck!

For more Blogs Related To Julia, Check below links:

Start Machine Leaning With Julia: Top Julia Libraries For Machine Learning

Data Visualization In Julia Using Plots.jl: With Practical Implementation

You can check my articles here: Articles

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