Backus Naur(BNF)

• What is an integer?

  A whole number
• What does BNF stand for?

  Backus-Naur Form
• What is the purpose of BNF?

  To define the syntax of a language
• What does syntax refer to in programming?

  The definition of allowed patterns in a language
• What is an example of a defined format for 'char'?

  One character in length
• What characters are allowed in the 'char' format?

  1. z, A-Z, 0-9, @£$
• What does the notation ': : =' mean in BNF?

  Means is defined by / consists of
• What does '< >' signify in BNF?

  It indicates a syntactic item
• What does '|' represent in BNF?

  It means OR
• What does '{ }' denote in BNF?

  It means optional
• What does ',' signify in BNF?

  It means AND
• What is the purpose of defining 'char2' in BNF?

  To create a new data type
• What does the meta level refer to in BNF?

  Decomposing elements into smallest parts
• How is a number defined in BNF?

  As 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
• How is a letter defined in BNF?

  As a | b | c | d | e | f | g | h | i | j | k | l | m | n | o | p | q | r | s | t | u | v | w | x | y | z
• What are the components of the BNF definition for 'char2'?

  • <char2> : : = <number> <number>
  • <number> <letter>
  • <letter> <number>
  • <letter> <letter>
• Why is BNF important in programming?

  It standardizes language syntax definitions
• Name two scenarios where BNF might be used.

  Defining programming languages and data formats
• How does BNF make programming easier?

  By providing clear syntax rules
• What does the notation <WORD> : : = <LETTER> <LETTER> represent?

  Definition of a word with 2 letters
• How can you define a word using BNF notation?

  <WORD> : : = <LETTER> | <LETTER> <LETTER> | <LETTER> <LETTER> <LETTER>
• How would you define a sentence using BNF incorporating the definition of a word?

  <SENTENCE> : : = <WORD> | <WORD> ‘,’ {<WORD>}
• What is a syntax diagram?

  • A visual representation of BNF
  • Shows how symbols are connected
  • Helps in understanding language structure
• How are the symbols for LETTER defined in the syntax diagram?

  <LETTER> : : = A | B | C | D
• What is the role of circles in the syntax diagram?

  To represent undefined symbols like LETTER