Declare in Julia

To declare a class in Julia, you use the struct keyword followed by the name of the class and the properties of the class that you want to define.

For example, let's declare a simple Person class with name and age properties:

struct Person 
    name::String 
    age::Int 
end

This defines a class called Person, with properties name of type String and age of type Int.

You can also add methods to your class for behavior. Here is an example of adding a method to the Person class:

struct Person 
    name::String 
    age::Int 
end
 
function introduce(p::Person)
    println("Hi, my name is $(p.name) and I am $(p.age) years old.")
end

This introduce function prints out the name and age of the person.

Now, let's create an instance or object of the Person class:

p = Person("John", 27)

This creates a new instance of the Person class with the name John and age 27.

Finally, we can use the method we defined earlier to introduce the person:

introduce(p)

This prints out "Hi, my name is John and I am 27 years old."