Execution Tracing

Question 1

How to know when a program is correct

Answer 1

• any given input can take and create the right answer and the program has the ability to stop at any point
• implementation of algorithms meet specifications set out for them

Question 2

Types of software testing

Answer 2

white/glass box

black box

Question 3

White box testing

Answer 3

• structural or code based testing
• full knowledge of the code being tested and how it was written
• usually by code developers or someone allowed to examine the code in detail
• small components of larger software tested in isolation

Question 4

Boundary testing

Answer 4

• test data is chosen for its proximity to any max/mins written into the program
• test a list length to approach its limit, to reach or exceed it and then fix with errors

Question 5

Black box testing

Answer 5

• aka behavioural testing
• assumes testers ignorance of internal source code
• conduct tests to check program against specification
• test for ease of use, aesthetics, performance etc

Question 6

automated testing

Answer 6

• a lot of research effort goes into software that tests together
• the goal is to automate some repetitive but necessary testing in the formalized process or testing difficult to do manually

Question 7

Execution tracing

Answer 7

• tracking the course of a running program’s execution

- temporarily insert print() statements to show the values of certain variables at certain points

Question 8

pausing execution

Answer 8

simple technique without any debugging tools to insert a print() followed by keyboard input

Question 9

issues with manually pausing execution

Answer 9

• need to insert a lot of code for line-by-line investigation
• need to tidy up code after tracing (IE deleting the testing code)

Question 10

IDE Debugging Tools

Answer 10

• suspend program execution temporarily at designated places called breakpoints
• allow viewing values of variables in scope at a breakpoint
• set and clear breakpoints
• suspend program
• debugger

Question 11

IDLE debug control

Answer 11

Go
stop
over
out
quit

Question 12

Go

Answer 12

resume execution, stop at next breakpoint if any or to end of program

Question 13

step

Answer 13

execute the current instruction and suspend execution again

if the current instruction is or contains a function call, then step into that function and suspend execution there

Question 14

over

Answer 14

same as step, except if the current instructions is or contains a function that call will be “stepped over” and the program will be suspended at the start of the next instruction in the current block

Question 15

out

Answer 15

resume execution until the current block is finished executing or step out of a function if the execution is currently one

Question 16

quit

Answer 16

exit program