ComProg 1 Midterms

• Computer Program - a structured sequence of instructions written in a specific programming language that directs a computer or digital system to perform a series of tasks or calculations
• Typically, a program has:

  • Source code
  • Control flow
  • Data structures
  • Input/Output (I/O)
  • Error handling
• Python Indentation - refers to the spaces at the beginning of a code line. Python uses it to indicate a block of code.
• Where in other programming languages the indentation in code is for readability only, the indentation in Python is not that important. False
• Variables are used to store information to be referenced and manipulated in a computer program.
• Variables also provide a way of labeling data with a descriptive name, so our programs can be understood more clearly by the reader and ourselves.
• Data Types are the classification or categorization of data items.
• Data Types represents the kind of value that tells what operations can be performed on a particular data.
• Data Types are categorized into Primitive and Non-primitive Data Types
• Examples of variables with common primitive data types:

  • my_birthday = “September 25, 2000” → String Data Type
  • my_age = 100 —> Int Data type
  • my_weight = 65.4 —> Float Data type
  • I_am_old = True —> Boolean Data type
  • Wala_lang = None
• Identifying variable data types

  
  

  A variable's type determines the values that the variable can have and the operations that can be performed on it

  x = “hello”

  print(type(x)) →outputs <class 'str'>

  print(isinstance(x, str)) —>outputs true
• Data type conversion refers to the process of changing the representation of data from one data type to another.this is to ensure that data types will adhere to the logic of our program.
• Data Structures - Also called “collections”, they are built-in types that allow you to store and manipulate collections of data. They can contain different types of data
• Data Structures - Elements can be accessed by index if the collection is indexed
• Lists

  
  

  Are created using square brackets []

  my_???? = [1, 2, 3, “four”, 3, 4.0]

  Ordered, mutable (can be changed), indexed, and allows duplicate elements.
• Tuples

  
  

  Created using round brackets ()

  my_???? = (1, 2, 3, 4, True)

  Ordered, immutable (cannot be changed after creation), indexed, and allows duplicate elements.
• Sets

  Created using curly braces {}

  my_???? = {1, 2, 3.5, “hello”}

  unordered, unchangeable* (but you can remove or add items in it), and unindexed.
• Dictionary

  Created using curly braces {} and contains keys and values by pair

  my_???? = {'name': 'Bentong', 'age': 99}

  ordered*,unindexed, changeable and do not allow duplicates.
• Conditionals allow a program to execute certain pieces of code based on whether specific conditions are met.
• Conditionals enable decision-making within the code, allowing

  different outcomes depending on varying inputs or states.
• Programming languages evaluates conditions to be either true or false
• Complete the image:

  A) True

  B) False

  C) Condition

  
• For conditions to be evaluated, we use comparison operators

  ● == is equal to

  ● != not equal to

  ● > greater than

  ● < less than

  ● >= greater than or equal to

  ● <= less than or equal to
• Alongside comparison operators we also use logical operators to combine conditional statements

  ● and (both conditions must evaluate to true)

  ● or (only one of the conditions must evaluate to true)

  ● not (reverses the truth value of a condition)
• Conditionals

  ● if statement

  ● if else statement

  ● if elseif/elif else statement

  ● switch statement (available as “ match case ” in python 3.10 and up)

  ● Ternary operator
• A loop is a programming construct that repeats a block of code as long as a condition is true.
• Loops help automate repetitive tasks, making code more efficient and readable.
• Types of loops in Python

  ● for loop: Used for iterating over a sequence (like a list, tuple, dictionary, string,

  or range).

  ● while loop: Repeats as long as a specified condition is true.
• Loop Controls

  The flow of the loop can also be controlled to our preference.

  ● break: Exits the loop prematurely.

  ● continue: Skips the rest of the code inside the loop for the current iteration

  ● pass: Does nothing; it’s a placeholder
• Looping best practices

  ● Avoid infinite loops.

  ● Ensure loop conditions will eventually be false.

  ● Use appropriate loop types for different scenarios.
• Lists

  • Ordered
  • mutable (can be changed)
  • indexed
  • allows duplicate elements.
• Tuples

  • Ordered
  • immutable (cannot be changed after creation)
  • indexed
  • allows duplicate elements.
• Sets

  • unordered
  • unchangeable* (but you can remove or add items in it)
  • unindexed
  • (does not allow duplicate values)
• Dictionary

  • ordered*
  • changeable
  • unindexed
  • do not allow duplicates
• Source code: Human-readable instructions written in a language like Python, Java, or C++.
• Control flow: Logical constructs like loops, conditionals, and functions that manage the sequence of operations.
• Data structures: Ways to store, organize, and retrieve data efficiently (e.g., arrays,

  lists, trees, variables).
• Input/Output (I/O): Mechanisms for interacting with the outside world, such as reading input from users or files and producing output.
• Error handling: Techniques to manage and recover from unexpected conditions or

  mistakes (e.g., exceptions, validation checks). (real-time debugging vs compile-time

  debugging)