computer science paper 2 - algorithms

send help

how to print uppercase

how to print uppercase

print(Name.upper())

how to print lowercase

print(Name.lower())

how to print length of a string

len(password)

what is slicing a string called

substring

wat does word[2:5] mean

substring beginning at 2 and ending at 5 forms

if [4:], what?

4 characters of the string from the right

if [:4], what?

4 characters of the string from the left

how to close a file

file.close()

how to read txt in file

file.readline()

how to write a file

file.write(“text\n”)

how to show end a file

endofFile = false

how to open a file

file = open(“file.txt”, ”r”)

how to make new file

file = open(“file.txt” , “w”)

how to append file

file = open(“file.txt” , “a”)

a file is the __ of the table

a record is the __ of the table

column ; row

what is put at the end of an SELECT FROM WHERE command

;

how to create 2D array

array = [],[]

how does sub program simplify a program

by breaking it into smaller more managle partsw

hat are parameters

values that are passed into a sub program

what is the difference bewteen a function and a procedure

functions return values while a procedure doesn’tho

how do you call a function

just the name of the function but with the ()

2 stepper for using random number generator in python

inport random

random.randint(1,10)

A variable is a ___ location that holds data that during the execution of a program, can change

named memory

how to find the remainder after division

MOD

how to find the whole number after division

DIV

is it <= and >= or =< and =>

< is always first

what are the 3 core programming constructs and explain their uses

Sequence - lines of code and run int he order that they are written

Selection - the flow of a program is changed depending on conditions

Iteration - loop (for i=0 to )

3 qualities of low level language

directly translates to machine code

direct control over hardware

written for specific processors

compare 3 differences between machine code and assembly code

1. first generation vs second generation

2. directly executable (binary) vs translates to machine code

3. binary vs text abbreviations of commands

translator turns … into …

source code into machine code

example of one low level translator

assembler

examples of 2 high level translators

compiler and interpreter

what is the difference between a compiler and an interpreter

compiler translates the source code all in one go while interpreter does it line by line

IDE makes writing … more ….

high level languages more efficient

what are 4 components of an IDE

1. editor

2. error diagnostics

3. run time environment

4. translator

4 functions contained within editor

1. code text font size

2. colour of text

3. comments

4. autocomplete ()

2 functions with error diagnostics

identifier - syntax errors

debugging - logic errors

what does run time environment do

allow the IDE to run the program

what does translator do

inbuilt software for compiling and interpreting code

3 examples of potential errors

Peripheral, Disk, Communication errors

what is defensive design

when every possible input from the user is considered

5 types of input validation

- length - of string 

- type - of data

- range - of number 

- presence - of whether any data present 

- format - of whether data is in the correct format 

program maintainability means

programmers can understand each other’s code

iterative testing: each … tested during development

final testing: all … of program function as intended 

pathway; modules

types of tests [4]

normal, boundary, erroneous ( wrong data type) , invalid

syntax error is an error that breaks the … rules of a programming language and stops it from running

grammatical

3 main principles of computational thinking:

Abstraction - removing unnecessary details

Decomposition - breaking into smaller tasks

Algorithmic thinking - creating step-by-step instructions in order to produce a solution to a problem

A binary search keeps … a dataset by comparing the target value with the … value, going left if smaller, right if bigger, until it finds the value or realises it's not there

halving; middle;

… sort starts at the beginning and checks values in pair; if not correct order = swapped

bubble