Topic 2: Programming fundamentals

• What is the purpose of variables in programming?

  Variables store data in memory locations that can change during program execution.
• How does the value of a variable change during program execution?

  The value of a variable can change as the program runs and processes data.
• What is an identifier in programming?

  An identifier is a unique name that refers to a location in memory where data is stored.
• What defines the type of data that can be stored in a variable?

  The data type defines the type of data that can be stored at the memory location and the operations that can be performed on it.
• Why can't you multiply two words in programming?

  You cannot multiply two words because multiplication is not defined for string data types.
• In some programming languages, when are variables declared?

  Variables are declared at the start of a program to reserve the appropriate amount of memory.
• How does variable declaration differ in Python compared to other languages?

  In Python, variables do not need to be declared; the data type is inferred from the assigned value.
• What happens when you assign a value like -23 to a variable in Python?

  The variable will be stored as an integer.
• Why is it important to understand different data types in programming?

  Understanding different data types is crucial for effectively working with variables in programs.
• What are the typical memory requirements for different data types?

  • Integer: 2 or 4 bytes
  • Single: 4 or 8 bytes
  • Character: 1 byte
  • String: 1 byte per character
  • Boolean: 1 byte
• What type of data does an integer variable store?

  An integer variable stores whole numbers such as 3, 45, or -453.
• What type of data does a single variable store?

  A single variable stores numbers with a fractional part such as 34.450 or 4.0.
• What does a character variable store?

  A character variable stores a single character, which can be a letter, digit, punctuation mark, or symbol.
• What does a string variable store?

  A string variable stores zero or more characters and can be empty, just one character, or several characters.
• What values can a Boolean variable have?

  A Boolean variable can have the value True or False.
• What is the focus of section 7.1 in the study material?

  Programming fundamentals
• Why might different programming languages have different names for data types?

  Because each programming language has its own syntax and conventions
• How many bytes might an integer require in different programming languages?

  It can require either 2 bytes or 4 bytes
• What is the purpose of assignment statements in programming?

  To assign values to variables
• What is an example of a constant in programming?


  VAT_RATE = 0.2
• What are the two main benefits of declaring a constant?

  1. Easier to update values in one place; 2. Code is easier to read and understand
• How are constants typically declared in Python?

  By using an assignment statement
• What convention is used in Python to indicate a constant?

  Identifiers for constants are written in uppercase
• What is the general structure of input and output statements in programming?

  • Input statement prompts the user for data
  • Output statement displays results to the user
• What pseudocode would you write to ask the user for their name and display a greeting?

  my_name = input("Please enter your name: "); print("Hello", my_name)
• What types of operations can be performed on numerical data types?

  Arithmetic operations and comparison operations
• What are the arithmetic operations that can be performed on numerical data types?

  • Addition
  • Subtraction
  • Multiplication
  • Division
  • Exponentiation
  • Integer division (DIV)
  • Modulus (MOD)
• What is the result of the operation $25 +$$3$?


  $28$
• What does the DIV operator do?

  Performs integer division
• What does the MOD operator return?

  The remainder of integer division
• How do you declare variables for integer and real numbers in Pascal?


  Var num1, num2: integer; Var answer: real;
• What is casting in programming?

  Changing the type of a variable value from one type to another
• How would you convert a string to an integer in Python?

  Using the int() function
• What happens when you add two strings in Python?


  They are concatenated
• What is the corrected pseudocode to add two numbers input as strings?

  num1 = int(input("Please enter first number")); num2 = int(input("Please enter second number")); sum = num1 + num2
• What does the float() function do?

  Changes a string variable to a floating-point number
• What are the built-in functions for string manipulation in programming?

  • Get length: stringname.length
  • Get substring: stringname.substring(startingPosition, numberOfCharacters)
  • Convert cases: stringname.upper, stringname.lower
  • Find position: stringname.index("character")
• How do you get the leftmost four characters of a string in OCR Exam Reference Language?


  Using stringname.left(4)
• What does the ASC function do?

  Converts a character to its ASCII decimal number
• What does the CHR function do?

  Converts an ASCII decimal number to its corresponding character