Unit 3.1 Variables and Assignments

Key points:

  • Variables are abstractions within programs which represent a value
  • Values can be individual data points or a list/collection that contains many data values
  • Types of data: numbers, Booleans (T/F), lists, and strings

Variables and Assignments (Python)

  • To define a variable, simply type in the variable name and use the equal sign to set it equal to its value
  • Variable can be defined using numbers, string, list, or boolean (strings must have quotations around it and lists must be surrounded by square brackets)
  • Dictionaries
  • Interchanging variables
  • Floats
  • Even Function

Variables and Assignments (JavaScript)

  • One way to assign a variable is doing var (variable name) = value;
  • Another way to assign a variable is using const (variable name) = value;

Unit 3.2 Data Abstraction

Key points:

  • Data abstraction provides a separation between the abstract properties of a data type and the concrete details of its representation
  • Data abstraction manages complexity in programs by giving a collection of data a name without referencing the specific elements of the representation
  • Data Abstraction makes it easier to implement, develop, and maintain code
  • The use of lists allows for multiple related values to be treated as a single value

Unit 3.3 Expressions

  • the symbol for exponent is “**”
  • the symbol for addition is “+”
  • the symbol for subtraction is “-“
  • the symbol for multiplication is “*”
  • the symbol for division is “/”
  • the symbol for modulus is “%”
  • an algorithm is a sequence of steps that are made to perform a specific task repeatedly.

Unit 3.4 Strings

Pseudo Code

  • Pseudo code is writing out a program in plain language with keywords that are used to refer to common coding concepts
  • Does not use actual code
  • Can be used to explain a concept about coding to someone who has no experience with
  • Begins at index 1

Length

  • The length of a string in coding is essentially the number of coding units or characters present in a string. For example, the length of the string “hello” would be 5.

Concatenation

  • Concatenation is basically joining two strings together to form one string. For example, one could concatenate the strings “hello” and “world” in order to make a single string that says “hello world”

Substring

  • A substring is a subset or a part of another string. For example, “hello” would be considered a substring in the string “hello world”.

3.1-3.4 Takeaways

Overall, I felt that I was able to learn a lot from other students teaching us these concepts (data abstraction, assignments, etc.). I also believe that I will find these notes very useful for when I study for the AP Exam as well as when I work on my Create Performance Task.