Private method in Julia

In Julia, a private method refers to a function that is accessible only within the module in which it is defined. To define a private method, the keyword private is used before the function declaration.

Here is an example:

module MyModule
export public_method
function private_method()

    println("This is a private method")

end
function public_method()

    println("This is a public method")

    private_method()

end
end

In this example, the module MyModule defines two functions - private_method and public_method. The private_method is defined as a private method using the private keyword. The public_method is defined as a public method and it calls the private_method.

If we try to call the private_method from outside the module, we will get an error because it is not accessible outside of the module:

julia> MyModule.private_method()
ERROR: UndefVarError: private_method not defined
Stacktrace:
 [1] top-level scope at REPL[2]:1

However, we can call the public_method from anywhere because it is a public method:

julia> MyModule.public_method()
This is a public method
This is a private method

In this example, the public_method calls the private_method successfully because they are both defined within the same module.

In summary, private methods are useful in Julia to hide implementation details of a module from other modules or programs and to prevent unintended usage of certain functions.