1.2.3 Intro to Programming [OUT OF SERVICE] Flashcards
Programming construct: Sequence
Code is executed line-by-line from top to bottom
Programming construct: Selection
Certain block of code is run if a specific condition is met, using IF, ELSE IF and ELSE statements
Programming construct: Iteration
A block of code is executed a certain number of times or while a condition is met, using FOR, WHILE or DO UNTIL loops
What is a variable?
A name used to refer to a particular memory location used to store data.
What operator is this: =
Assignment
What is the difference between constants and variables?
Value of a constant cannot be edited by the program during execution.
What might we use a constant for?
Values that don’t need changing.
EG: VAT, Pi
Programming construct: Subroutine
Named blocks of code that perform a specific task.
How many values can a function return?
One.
What are parameters?
Values passed into a subroutine.
Arithmetic operator: **
Exponentiation (raising a number to a power)
Arithmetic operator: DIV or //
Integer division
Whole number of times a number goes into another
Arithmetic operator: MOD
Remainder when a number is divided by another
What are arithmetic and relational operators used for?
Arithmetic: Carrying out mathematical functions
Relational: Making comparison between 2 values
Boolean operator: AND
Returns true when both values true
Boolean operator: OR
Returns true when at least one value is true
How do you get the length of a string?
stringname.length
What is a substring?
A section within a string
How do you get a substring?
stringname.subString(startPos, numOfChar)
How can you open a file to read?
myFile = openRead(“filename.txt”)
How can you read a line from a file?
fileContent = myFile.readLine()
How can you close a file?
myFile.close()
How can you open a file to write?
myFile = openWrite(“filename.txt”)
How can you write a line to a file?
myFile.writeLine(“Lovely weather outside”)
What is the end of the file given by?
endOfFile()
Why is assembly easier to use than machine?
It uses mnemonics.
What is each assembly language mnemonic represented by?
A numerical code.
Why are assembly language commands processor specific?
They interact directly with the CPU’s registers.
What sort of system might assembly language be used in? Why?
Embedded system, due to direct interaction with hardware
Mnemonic Function: ADD
Add the value at the given memory address to the
value in the Accumulator
Mnemonic Function: SUB
Subtract the value at the given memory address from the value in the Accumulator
Mnemonic Function: STA
Store the value in the Accumulator at the given
memory address
Mnemonic Function: LDA
Load the value at the given memory address into the
Accumulator
Mnemonic Function: INP
Allows the user to input a value which will be held in
the Accumulator
Mnemonic Function: OUT
Prints the value currently held in the Accumulator
Mnemonic Function: HLT
Stops the program at that line, preventing the rest of
the code from executing.
Mnemonic Function: DAT
Creates a flag with a label at which data is stored.
Mnemonic Function: BRZ
Branches to a given address if the value in the
Accumulator is zero. This is a conditional branch.
Mnemonic Function: BRP
Branches to a given address if the value in the
Accumulator is positive. This is a conditional branch.
Mnemonic Function: BRA
Branches to a given address no matter the value in
the Accumulator. This is an unconditional branch.
