paper 2 all

• If statement example for pseudocode?

  
  

  if > 17 adult else child

  IF Age > 17 THEN

  
  

  OUTPUT "You are an

  adult"

  ELSE

  
  

  OUTPUT "You are a child"

  ENDIF
• CASE OF example in pseudocode?

  
  

  n

  CASE OF OpValue

  
  

  "+" : Answer = Number1 + Number2

  
  

  "-" : Answer = Number1 - Number2

  
  

  "" : Answer = Number1Number2

  
  

  "/" : Answer = Number1 / Number2

  
  

  OTHERWISE OUTPUT "invalid operator")

  
  

  ENDCASE
• For counter Pseudocode example?

  FOR Counter <- 1 TO 10 STEP 2

  OUTPUT Counter

  NEXT Counter
• For counter python example with step 2?

  for Counter in range (1,10,2):

  
  

  print (Counter)
• What is a count-controlled loops

  loop for a set number of iterations
• What is a pre-condition loops


  may have no iterations
• What is a post-condition loops


  always has at least one iteration.
• what in python and pseudocode is a count-controlled loop

  FOR TO

  
  

  
  

  NEXT

  
  

  
  

  and

  
  

  
  

  for i in range ():
• what in python and pseudocode is a pre-conditioned loop

  WHILE, ENDWHILE

  
  

  &

  
  

  while :
• while loop in pseudocode

  WHILE TotalWeight <

  100

  
  

  TotalWeight = TotalWeight + Weight

  
  

  ENDWHILE
• what in python and pseudocode is a post-conditioned loop

  REPEAT

  
  

  UNTIL

  
  

  or

  
  

  (python only uses pre conditioned loops
• repeat pseudocode example

  REPEAT

  
  

  NumberOfItems

  = NumberOfItems + 1

  
  

  UNTIL NumberOfItems > 19
• How do you find the length of a string in PS and PY


  LENGTH ("Computer Science")

  
  

  len ("Computer Science")
• for substring in pseudocode how would you extract 'Science' from 'Computer Science'

  1st First parameter is the string

  
  

  2 second parameter is

  Position of the start character,

  
  

  3rdparameter is the length of the

  required substring.

  
  

  Pseudocode strings start at position one.

  
  

  SUBSTRING ("Computer Science", 10, 7)
• substring in python?


  "Computer Science" [9:16]

  
  

  1st index is start position of substring

  
  

  2nd index is end position of substring

  
  

  python starts at position 0
• how to do upper and lower case in pseudocode?

  UCASE ("Computer Science")

  
  

  LCASE ("Computer

  Science")
• how to do upper and lower case in python?

  MyString.upper()

  
  

  "Computer Science". lower ()
• file opening python


  f = open("demofile.txt", "r")

  print(f.read())
• procedure

  perform certain tasks in a particular order on the basis of the given inputs.

  
  

  A procedure cannot be called using any function

  
  

  these can be called repeatedly, and we don't have to compile them every single time.
• function

  calculate the results of a program on the basis of the given input.

  
  

  A function can be called using a procedure.

  
  

  compilation of a function occurs when we call them in a program.
• file closing python


  f = open("demofile.txt", "r")

  print(f.readline())

  f.close()
• writing to an existing file python

  f = open("demofile2.txt", "a")

  f.write("Now the file has more content!")

  f.close()
• how to create and call a function in python?

  def my_function():

  print("Hello from a function")

  
  

  my_function()
• how to delete in an SQL statement

  DELETE FROM table_name

  
  

  WHERE some_column=some_value
• order by in SQl statemnt

  SELECT column_name(s)

  FROM table_name

  ORDER BY column_name [ASC|DESC]
• select all in sql statement

  SELECT *

  FROM table_name
• linear search


  Searching is used to check if a value is stored in a list.

  
  

  It is done systematically by working through all the items in the list.

  
  

  Linear search will inspect each item in a list in turn to see if it matches the value searched for.
• bubble search


  When searching through lists it can sometimes be more effective if the list is already sorted.

  E.g. Names could be alphabetical and numbers could be in numerical order

  
  

  Here each element in the list is compared to the next one and swapped if the elements are in the wrong order.

  
  

  Starts with the first element and finishes at the next to last one.

  
  

  Once it gets to the end of the list we can be sure that the last element is in the correct place.

  
  

  It must now go back to the start and re do the process as other elements may still be out of order.
• VA - Range checks


  checks that the value of a number is between an upper value and a lower value e.g checking percentage marks are between 0 and 100.
• VA - Length checks


  checks that the data contains exact amount of characters e.g password can only be 9 characters
• VA - Type checks


  Checks that the data entered is of a given data type e.g that the numbers of brothers and sisters would be an integer
• VA - Character checks


  checks the number of characters meets

  expectations e.g 8 letter password needs 8 letters.
• VA - Format checks


  checks to ensure the characters entered confrom to a pre-defined pattern e.g birth date - DD/MM/YY
• VA - Presence checks


  checks to ensure that at least some kind of data has been entered and the value has not been left blank.
• VA - Check digits


  check digit is the final digit included in the code, it is calculaed from all the other digits in the code. E.g Bardcodes and products codes
• disadvantage of validation


  it cannot check that the data being entered is correct, it only checks to make sure it meets the requirements of the rules

  e.g. it can check a score is out of 100 but cannot tell that a score of 35 should have been 53
• VE - Double entry


  - Data has been entered twice, if the two things match the propgram will move on but if they dont match then the program will alert the user to re input.
• VE - Screen/visual check


  - a manual check is completed by the user who is entering data. The finished input data is displayed and the user must confirm if it is what they want to submit. If is not correct the user can reenter the data
• VE - Parity check


  - check whether data has been changed if corrupted following data transmission, this method is based on the numbers of 1s in a byte of data.
• VE - Checksum


  - a method to check if data has been changed or corrupted following data transmission. Data is sent in blocks, and an additional value called the checksum is sent at the end of the block of data.