Welcoming transfer students

[aubertc]

It would be nice to have some material for "transfer students", e.g., students that learned programming using e.g. Java or Python. Something a bit like what I have at https://spots.augusta.edu/caubert/teaching/general/java/

[aubertc]

Pages like https://en.wikipedia.org/wiki/Comparison_of_C_Sharp_and_Java could be useful.

[whmarsh87]

Java

C# and Java are similar enough that I would not expect too much difficulty for the adjustment from Java to C#. It's a little difficult for me to suss out exactly what I would recommend as, also being a transfer student, I did not take 1301. I would have also had my comparable class a decade ago, so I am fuzzy on that side of things as well.

What I would focus on would be the cliff note version of 1301. If certain libraries or functions are brought up, denote what they were and link to the docs page for them. I would also maybe go down the list of everything used in 1301 and call out differences in library structure, e.g. "In Java this task required library x and y; in C# you can do all of this with library z." or vice-versa.

It's been a while since I've written in Java, but re-looking into it, one difference would be that while in Java, nothing from java.lang needs imported, i.e. you can use System.out.println with no imports, but in C#, System must be imported to use Console.WriteLine would be an example of what I am referring to.

It might also be worth comparing import and package with using and namespace.

Python

With this, it might be first worth comparing how compiled and scripting languages differ. It would also be worth introducing typing and perhaps getting into why, despite not having declared types, types still existed in Python- they were just handled behind the scenes. For instance:

def add_and_print(x):
    x += 1

    print(x)

x = 2

add_and_print(x)

print(x)

will display:

3
2

and:

def add_and_print(x):
    x.append(5)

    print(x)

x = [1,2,3,4]

add_and_print(x)

print(x)

will display:

[1,2,3,4,5]
[1,2,3,4,5]

This is because, even without typing, types still exist. Primitives are still passed by value, objects are still passed by reference (and strings are still objects that pass by reference but have safety measures in place so that they seem to be treated like primitives- though that arguably is too much at this stage).

Another key distinction with Python, is there is no "main" that is getting written in; one just codes in the file with nothing really declared for where the code that is being executed sits. Python knows to ignore what follows the def with the tabs denoting how long that function code lasts for. What is not tabbed in is where the main stream of code is again. So, just a mention of what { and } are used to denote and the fact that that tabs, while still used for organization, do not actually signal to the compiler where various sections begin and end. Additionally, in Python does not require ; to mark the end of a line, so I would also suggesting calling that out as well.

If you are unfamiliar with Python and how it's "main" works, this code will do the same thing as the above:

x = [1,2,3,4]

def add_and_print(x):
    x.append(5)

    print(x)

add_and_print(x)

print(x)

The only thing python cares about is that add_and_print() is declared prior to it's use. Otherwise, it will let you go in and out of what's in "main" as much as you want. I would not recommend for organizational reasons, but it will let you.

Otherwise, I would say it can be very similar to the Java section, to where only the functionalities discussed in 1301 really need to be covered.

Overall

I would start by formulating a list of what was covered in 1301 and what from that is essential for a student to progress in 1302. With no context for what is covered in 1301, I'll need more information on that course to delve into this in more detail.

[whmarsh87]

And as an aside, if you want an understanding of how cursed Python will let you code things:

x = 0

if x == 0:

    x = 2

    def add_and_print(x):
        x += 1

        print(x)

add_and_print(x)

print(x)

will also work, but:

x = 2

if x == 0:

    x = 2

    def add_and_print(x):
        x += 1

        print(x)

add_and_print(x)

print(x)

will throw an error because add_and_print() only get defined if x== 0. That said, a really bad design, but I guess where you could practically use it:

x = 2

if x == 0:

    def add_and_print(x):
        x += 2

        print(x)

else:
    def add_and_print(x):
        x += 1

        print(x)

add_and_print(x)

print(x)

will print

3
2

and:

x = 0

if x == 0:

    def add_and_print(x):
        x += 2

        print(x)

else:
    def add_and_print(x):
        x += 1

        print(x)

add_and_print(x)

print(x)

will print

2
0

Again, would not recommend, but it's kind of a manner in which you could leverage it allowing you to declare functions not off the "main".

[whmarsh87]

With my mind on that behavior, something actually worth calling out to students coming from Python is that scope of variables exists in C#. So something like:

y = 0

if y == 0:

    x = 0

    def add_and_print(x):
        x += 2

        print(x)

else:

    x = y * 1

    def add_and_print(x):
        x += 1

        print(x)

add_and_print(x)

print(x)

will still be fine in Python because x still exists outside the scope of if. Once it is declare, it is just declared.