PLS

• What do the <> symbols indicate in PLS?

  They indicate where values need to be supplied
• What character indicates a comment in PLS?

  #
• What are identifiers in PLS?

  Sequences of letters, digits, and underscores
• What is the first character of an identifier?

  It must start with a letter
• How are data types assigned to variables in PLS?

  Explicitly during declaration or implicitly during initialization
• What are the supported primitive data types in PLS?

  • integer (int)
  • real (float)
  • Boolean (bool)
  • character (str)
• What is the purpose of conversion in PLS?

  To transform the data types of variable contents
• How are constants named in PLS?

  In all uppercase characters
• What does combining declaration and initialization imply?

  The data type is implied when a value is assigned
• What are structured data types in PLS?

  • Sequence of items, each typed
  • Start with an index of zero
• What is a string in PLS?

  A sequence of characters
• What is an array in PLS?

  A sequence of homogeneous items
• What is a record in PLS?

  A sequence of heterogeneous items
• How many dimensions does PLS support?

  Two dimensions
• What does PLS not support regarding data structures?

  Ragged data structures
• What are the arithmetic operators in PLS?

  • / : division
  • * : multiplication
  • ** : exponentiation
  • + : addition
  • - : subtraction
  • // : integer division
  • % : modulus
• What are the relational operators in PLS?

  • == : equal to
  • != : not equal to
  • > : greater than
  • >= : greater than or equal to
  • < : less than
  • <= : less than or equal to
• What are the logical/Boolean operators in PLS?

  • and : both sides must be true
  • or : either side must be true
  • not : inverts the value
• What is the purpose of assignment in PLS?

  To set or change the value of a variable
• How is sequence structured in PLS?

  Instructions come one after the other
• What indicates blocking of code segments in PLS?

  Indentation and subprogram calls
• What is the selection structure in PLS?

  • if <expression>: <command>
  • if <expression>: <command> else: <command>
  • if <expression>: <command> elif <expression>: <command> else: <command>
• What does the 'if' statement do in PLS?

  Executes command if expression is true
• What is the purpose of 'elif' in PLS?

  To check another expression if the first is false
• What does the 'else' statement do in PLS?


  Executes command if previous expressions are false
• What is the repetition structure in PLS?

  • while <condition>: <command>
  • for <id> in <structure>: <command>
• What does the 'while' loop do in PLS?

  Executes command while condition is true
• What does the 'for' loop do in PLS?

  Executes command for each element in structure
• What is a count-controlled loop in PLS?

  Executes command a fixed number of times
• What does the 'range' function do in PLS?

  Generates a list of numbers
• What are the types of subprograms in PLS?

  • Procedures (with or without parameters)
  • Functions (with or without parameters)
• What does the 'def' keyword indicate in PLS?

  Defines a procedure or function
• What does the 'return' statement do in PLS?

  Returns a value from a function
• What are the input and output methods in PLS?

  • print(<item>): Displays item on screen
  • input(<prompt>): Returns user input
• What file operations are supported in PLS?

  • open, close, read, write, append
• How do you open a file for reading in PLS?

  <fileid> = open(<filename>, "r")
• What does <fileid>.readlines() do in PLS?

  Returns a list of lines from the file
• What does <fileid>.readline() do in PLS?

  Returns a line from the file
• How do you open a file for writing in PLS?

  <fileid> = open(<filename>, "w")
• How do you close a file in PLS?

  <fileid>.close()