Course Intro - Intro to Computer Science

# Welcome

Intro to Computer Science

---

# Agenda

1. [Introductions](#introductions)
2. [What you know you knew](#know-knew)
3. [What you didn't know you knew](#didnt-know-knew)
4. [What you knew you didn't know](#knew-didnt-know)
5. [What you didn't know you didn't know](#didnt-know-didnt-know)
6. [How this course works](#how-course-works)
7. [What to do now](#do-now)
8. [Conclusions](#conclusions)

---

# Introductions

---

## This course

Introduction to Computer Science

- Syllabus: [syllabus](/content/courses/intro-to-computer-science/syllabus/)
- Schedule: [schedule](/content/courses/intro-to-computer-science/schedule/)

---

Official description:

> How to design algorithms to solve problems and how to translate these algorithms into working computer programs. Experience is acquired through projects in a high-level programming language. Intended primarily for computer science majors but also suitable for students of other scientific disciplines. Programming assignments.

---

## Me

Foo Barstein

- discord: @foo.barstein

---

## You

- Probably an aspiring programmer.
- Perhaps an aspiring computer scientist.
- Hopefully interested in making things and solving problems.
- Willing to spend hours by yourself reading and staring at code.

---

## Computer science

The study of the theory and practice of computation. Very open-ended.

```python
not programming == computer_sciencing
```

```python
computer_sciencing.find(computers) == -1
```

```python
computer_sciencing not in sciences
```

---

# What you know you knew

---

## Data types

Programs usually think of data in terms of rigid stereotypes.

- integers
- floating point numbers
- booleans
- strings
- lists
- dictionaries/hash tables/associative arrays
- nonetypes/null/nil

Review [data types](/content/courses/intro-to-programming/data-types/).

---

## Input and output

There are many ways to input and output data from / to external sources.

```python
response = input("What's brown and sticky?")
```

```python
print("'{}' is correct!".format(response.capitalize()))
```

Review [input and output](/content/courses/intro-to-programming/input-output/).

---

## Boolean logic and decision-making

Programs can adapt to context.

```python
if this or that and the_other is not also_that:
    thats_wonderful()
```

Review [boolean logic](/content/courses/intro-to-programming/boolean-logic/) and [decision-making](/content/courses/intro-to-programming/decision-making/).

---

## Functions

Functions are modular blocks of code usually designed to perform a single task.

```python
def thats_wonderful():
    print("That's wonderful")
```

Review [functions](/content/courses/intro-to-programming/functions/).

---

## Modules

A module is a simply a reusable library of code.

```python
# import random module
import random

def thats_wonderful():
    # use a function from the random module
    if random.randint(1,10) > 5:
        print("That's wonderful")
    else:
        print("Okay...")
```

Review [modules](/content/courses/intro-to-programming/modules/).

---

## For loop and while loops

You have choices when repeating blocks of code.

```python
for i in range(10):
    print("Welcome!")
```

```python
i = 0
while i < 10:
    print("Welcome!")
    i = i + 1
```

Review [for loops](/content/courses/intro-to-programming/loops-for/) and [while loops](/content/courses/intro-to-programming/loops-while/).

---

## Lists

Lists are useful for storing a set of related values.

```python
favorite_foods = [
    "Pizza with glyphosate-coated bleached wheat flour and soy cheese",
    "Coffee with GMO corn syrup solids added",
    "Emulsified non-fat sugar-free ice cream with artificial sweetener"
    ]
```

Review [lists](/content/courses/intro-to-programming/list-basics/) and [more lists](/content/courses/intro-to-programming/list-more/).

---

## Dictionaries

Dictionaries contain key/value pairs.

```python
phone_numbers: {
    "Foo Barstein": "646-888-5623",
    "Baz Foo":      "212-717-3297",
    "Bar Baz":      "747-211-8451"
}
```

Review [dictionaries](/content/courses/intro-to-programming/dictionary-basics/) and [more dictionaries](/content/courses/intro-to-programming/dictionary-more/).

---

## Text files

Data can be stored and retrieved from text files.

```python
# open file in read mode
f = open('data.csv', 'r')
```

```python
# print out each line of the file
for line in f:
    data = line.split(",")
```

Review [text files](/content/courses/intro-to-programming/text-files/).

---

## Strings

Languages offer many ways to analyze and manipulate text data.

```python
text = "This,That,The other"
text = text.lower()
pos = text.find(",")
if pos > 0:
    data = text.split(",")
```

Review [strings](/content/courses/intro-to-programming/string-basics/) and [string formatting](/content/courses/intro-to-programming/string-formatting/).

---

# What you didn't know you knew

---

## Variables, literals, expressions, and function calls

There are many ways to express value in programs.

```python
"I am literally a literal"
```

```python
I_am_not
```

```python
math.pow(washington, 2) + park
```

Review [variables, literals, and expressions](/content/courses/intro-to-programming/variables-literals-expressions/).

---

## Dot notation

Dots indicate belongingness.

```python
random.randint(5, 10)
```

```python
math.pow(2, 2)
```

```python
'help me'.islower()
```

---

## Other languages

Try to convince me that you don't understand this code:

```js
let x = 5;
let y = true;
if (x < 10 and y == true) {
    console.log("Easy peasy!");
}
```

```java
int x = 5;
boolean y = true;
if (x < 10 and y == true) {
    System.out.println("Easy peasy!");
}
```

---

# What you knew you didn't know

---

A popular way to think about programs with interacting parts.

- Object-oriented programming

```python
you = new Student("Jane Doe")
```

```python
me = new Professor("Foo Barstein")
```

```python
me.say_hello(you)
```

Jump ahead half a semester to [object-oriented programming](../object-orientation/)

---

# What you didn't know you didn't know

---

## Basic computer concepts and terminology

Can you answer these questions?

- What is a file? What is a folder?

- What are good names for files and folders?

- How do you use the command line?

- What is a compiler? What is an interpreter? An assembler?

- What is an operating system? What is an application?

- What is the Internet? What is The World Wide Web?

- What is The Cloud?

Review [basic computer concepts](/content/courses/intro-to-computer-science/basic-computer-concepts/).

---

## Alias vs. copy

What is printed?

```python
x = 5
y = x
x = 10
print(y)
```

Try it out yourself.

---

## Raw strings

How many lines are printed?

```python
x = "First line\nSecond line"
print(x)
```

```python
x = r"First line\nSecond line"
print(x)
```

Learn about [raw strings](/content/courses/intro-to-programming/string-raw/).

---

## Multidimensional arrays

```python
row1 = [1, 2, 3]
row2 = [4, 5, 6]
row3 = [7, 8, 9]
```

```python
data = [row1, row2, row3]
```

```python
print(data[1][2])
```

Jump ahead half a semester to [multi-dimensional arrays](../arrays-multidimensional/).

---

## Recursion

How many times is the function called?

```python
def foo(x):
  if x < 3:
      foo(x+1)
      foo(x+1)

foo(1)
```

Jump ahead almost a semester to [recursion](../recursion/).

---

## You can place out of this class

If you are comfortable with multi-dimensional arrays, object-oriented programming, and recursion, consider taking a placement exam to skip this course.

Learn about [placement exams](https://cs.nyu.edu/home/undergrad/placement_sample_exams.html).

---

# How this course works

---

## Lecture

I will speak for 75 minutes about twice each week.... that's 150 minutes of talking each week.

I sincerely hope for your sake and mine that you will interrupt me and ask lots of questions.

---

## Notes

I write notes for most lecture topics. You may find them useful but incomplete.

---

## Slides

Students constantly request slides, so I have made them. However, I believe you are better off reviewing documents and code. Each slide has a link to its "source" document, which may be easier to read.

---

## Reading

Reading assignments from [the textbook](/content/courses/intro-to-computer-science/syllabus/#textbook) and elsewhere each class. The textbook is quite thorough.

---

## Assignments

You will have somewhere around 10 assignments.

You lose 10 points for each day late and we do not accept submissions more than 3 days late.

See the complete [lateness policy](/content/courses/intro-to-computer-science/syllabus/#late-policy).

---

## Extensions

Please do not ask for an extension.

You are hereby granted 2 free extensions for work submitted up to 3 days past the due date.

---

## Quizzes

Regular simple multiple-choice online quizzes. These are meant to help you self-assess your own mastery of conceptual material.

---

## Exams

You will take 3 exams.

Many find the first exam to be easy. The second and third... not so much!

Students who come to class tend to do better.

---

## Grading

- 25% quizzes
- 35% assignments
- 10% first exam
- 15% second exam
- 15% third exam

---

## Communication

We use Dicord for all communication outside of the classroom.

You must create a private channel in Discord.

Check the complete [Discord details](/content/courses/intro-to-computer-science/syllabus/).

---

## Tutoring

Tutors are waiting to answer your questions virtually all day every day of the week.

See them often. See them fast.

Check the complete [tutoring schedule](/content/courses/intro-to-computer-science/syllabus/#tutoring).

---

# What to do now

---

## Review the syllabus

The [syllabus](/content/courses/intro-to-computer-science/syllabus/) contains basic information on how this course works.

---

## Bookmark the schedule

The [schedule](/content/courses/intro-to-computer-science/schedule/) contains a day-by-day breakdown of everything you need to know and do in this course.

---

## Complete the consent form

Your consent is necessary since we use software that is not obliged to abide by the Family Educational Rights and Privacy Act.

[Complete the form](https://goo.gl/forms/uxxgA3D9F3kA0KAR2)

Contact me if you have concerns about privacy.

---

## Download and JDK version 8

The Java Development Kit (JDK) is a necessary set of tools that help develop Java programs. Install the Standard Edition (SE). We use the older version 8 because it is compatible with [Processing](https://processing.org), which we will use later in this course, whereas Processing is not compatible with newer versions of the JDK.

https://www.oracle.com/java/technologies/downloads/#java8

---

## Download and install Visual Studio Code

Visual Studio Code is an Integrated Development Environment (IDE) that integrates with the JDK to allow you to easily write and debug Java programs.

https://code.visualstudio.com

---

## Download and install the Extension Pack for Java

These extensions to Visual Studio Code make it suitable for Java programming.

https://marketplace.visualstudio.com/items?itemName=vscjava.vscode-java-pack

---

## Install Git

Get git [for Mac](https://git-scm.com/downloads) or [Git for Windows](https://gitforwindows.org/).

- Git for Windows additionally comes with Git Bash, which gives Windows users a UNIX-like command shell.
- WINDOWS USERS - you should use Git Bash or Windows Subsystem for Linux (WSL) rather than Windows' default Powershell or other command line shell program. To set Git Bash or WSL as the default terminal shell within Visual Studio Code, you can try to follow the instructions in [the second answer here](https://stackoverflow.com/questions/42606837/how-do-i-use-bash-on-windows-from-the-visual-studio-code-integrated-terminal) by **Mahade Walid** and edited by **FruityOatyBar** (ignore the first answe, which is outdated).
- Mac users already have a UNIX command shell in the Terminal app.

---

# Conclusions

- Welcome!

- Start to think like a compiler... or is it an interpreter... or an assembler?

```python
print("There's no reason to worry... {}".format("yet!"))
```

- Thanks. Bye.