Why does julia have multiple ways to define functions

function add(x, y)
    return x + y
end

add(x, y) = x + y

add = (x, y) -> x + y

Option 1: Using the `function` keyword

The first way to define functions in Julia is by using the `function` keyword. This is the most common and traditional way of defining functions in many programming languages. In this approach, we define the function using the `function` keyword, followed by the function name and the input arguments. The body of the function is enclosed within the `begin` and `end` keywords. The result is then returned using the `return` keyword.

function add(x, y)
    return x + y
end

In the above example, we define a function called `add` that takes two arguments `x` and `y`. The function body adds the two arguments together and returns the result using the `return` keyword.

Option 2: Using the assignment operator

Julia also allows us to define functions using the assignment operator `=`. This is a more concise and flexible way of defining functions. In this approach, we define the function name, followed by the input arguments, and then use the assignment operator to define the function body.

add(x, y) = x + y

In the above example, we define a function called `add` that takes two arguments `x` and `y`. The function body simply adds the two arguments together using the `+` operator.

Option 3: Using anonymous functions

Julia also supports the use of anonymous functions, which are functions without a name. Anonymous functions are defined using the `->` syntax. This approach is useful when we need to define a small, one-line function without the need for a separate function definition.

add = (x, y) -> x + y

In the above example, we define an anonymous function that takes two arguments `x` and `y` and adds them together using the `+` operator.

After considering the three options, the best approach to define functions in Julia depends on the specific use case and personal preference. The `function` keyword provides a more traditional and explicit way of defining functions, which can be useful for complex functions with multiple lines of code. On the other hand, the assignment operator and anonymous functions offer a more concise and flexible syntax, which can be beneficial for simple functions or when working with higher-order functions.