2.2 Programming Fundamentals

A value stored in memory that can change while the program is running

A value that does not change while the program is running, and is assigned when the program is designed

Giving a variable or constant a value

Converting a variable from one data type to another

A value is read from an input device e.g. keyboard

Data generated by the computer and displayed to the user

1) make a program easier to read as they are declared and assigned at the top of the program 2) can be changed easily by the programmer in one place in a program 3) instead of changing every instance of a value throughout a program 4) so less chance of errors 5) compiler can optimise code 6) which makes a program run more quickly

Inputs from the keyboard are always characters (multiple characters are called strings). However, for calculations, the ALU must use numbers so the string is cast to a number.

Executing one instruction after another

A program branching depending on a condition

Repeating sections of code

Count-controlled loops. Used when the number of iterations needed is known ahead of the iteration executing.

Condition-controlled loops. Used when the number of iterations is not known because the variable used to determine when the iteration ends is changing within the iteration itself

An alternative to WHILE where the code executes at least once before the condition is checked

int()

real()/float()

bool()

str()

ASC(b)

CHR(98)

for rolls in range():

while answer != “Computer”: answer = input(“Pass: “) endwhile

do answer = input(“Pass: “) until answer == “Computer”

end_of_file = False while not end_of_file