CISC 3140 FINAL QUESTIONS &
ANSWERS(RATED A+)
What are two actions that people involved in the Therac debacle could have taken to
reduce the damage that the machine caused? - ANSWERListen to and investigate
the end-user complaints
Test software successively and refine the old code, instead of relying on old code.
When is it incorrect to say "A computer program is a sequence of instructions to be
executed by a computer"? - ANSWERWith declarative programming
Name 1 imperative, 1 declarative, and 1 object-oriented language -
ANSWERImperative - Algol-60, Javascript
Declarative - Haskel or Mircosoft Excel
Object-Oriented - Java, C, C++
Name a programming language other than C++ or Java that can be used for Object-
Oriented Programming? - ANSWERPython
What kind of machine was the Therac-25? (What was the machine used for) -
ANSWERIt was an X-ray radiation therapy machine used to treat cancer patients.
What kind of machine was the Therac-25 (be careful here, the question is not what
was the machine used for, but what did it actually do)? - ANSWERLinear accelerator
that fired electrons.
In what country was the Therac-25 manufactured? - ANSWERCanada
What was one error in the Therac software that resulted in a death? -
ANSWERswitching too fast caused it to not be able to adjust to new setting
The Therac programmers engaged in several practices that either failed to prevent
errors from being included in production code or failed to repair programming errors
when incorrect program behavior was detected. Briefly state what two of those
detrimental practices were - ANSWERNever listen to end-user complaints
They did not properly test the software and failed to prevent errors
They denied the errors could exist and failed to repair them.
What was one government agency that was involved with dealing with Therac-25
problems? - ANSWERFDA in the USA and Health Protection Branch in Canada
Why is the Therac report of great importance to programmers - ANSWERBad
software kills people
, The Therac programmers engaged in several practices that either failed to prevent
errors - ANSWERPoor documentation. They did not listen to the end-user.
Insufficient testing
True or False? Replacement of a hardware lockout in a computer-controlled machine
by software will always result in faulty machine operation. - ANSWERFalse. We
need to verify the new hardware is compatible with the software. If the hardware is
compatible, the only limitation is the implementation of the software.
Imperative Programming - ANSWERBy definition, an imperative language tells the
computer what to do
Declarative Programming - ANSWERState what we want without telling the machine
how to do it.
OOP - ANSWERState what we want in the form of objects
What are the three programming paradigms - ANSWERImperative, Declarative,
Object-Oriented
What is one advantage declarative programming languages have over imperative
programming languages? - ANSWERa) declarative programming languages will
figure out how to do the task by themselves as opposed to imperative programming
languages that would have to program how to do the task.
b) It hides the machine. Instead of deciding how to do something, the programmer
can focus on what they want done
c) Declarative languages let go of memory constrain
Give an example of a programming situation in which the C programming language
would be a language of choice? - ANSWERWhen the program needs to be in real-
time
Programming operating systems
Why is the C/C++/Java programming language a poor choice for programming
scientific applications? - ANSWERcomplex arithmetic is poorly supported - no
complex arithmetic
Why should C/Java not be used to write business programs? - ANSWERC/Java
does not have precise decimal arithmetic
Why is Java not the best choice of programming language for business programs? -
ANSWERIt does not support decimal arithmetic. COBOL does decimal arithmetic
Why contrary to all too frequently popular opinion, are Fortran, Cobol and Prolog not
"dead languages" despite their age?( - ANSWERBecause they do their job well. A
language that does something well will endure.
Because they do exactly what they are designed to do and they do it well
ANSWERS(RATED A+)
What are two actions that people involved in the Therac debacle could have taken to
reduce the damage that the machine caused? - ANSWERListen to and investigate
the end-user complaints
Test software successively and refine the old code, instead of relying on old code.
When is it incorrect to say "A computer program is a sequence of instructions to be
executed by a computer"? - ANSWERWith declarative programming
Name 1 imperative, 1 declarative, and 1 object-oriented language -
ANSWERImperative - Algol-60, Javascript
Declarative - Haskel or Mircosoft Excel
Object-Oriented - Java, C, C++
Name a programming language other than C++ or Java that can be used for Object-
Oriented Programming? - ANSWERPython
What kind of machine was the Therac-25? (What was the machine used for) -
ANSWERIt was an X-ray radiation therapy machine used to treat cancer patients.
What kind of machine was the Therac-25 (be careful here, the question is not what
was the machine used for, but what did it actually do)? - ANSWERLinear accelerator
that fired electrons.
In what country was the Therac-25 manufactured? - ANSWERCanada
What was one error in the Therac software that resulted in a death? -
ANSWERswitching too fast caused it to not be able to adjust to new setting
The Therac programmers engaged in several practices that either failed to prevent
errors from being included in production code or failed to repair programming errors
when incorrect program behavior was detected. Briefly state what two of those
detrimental practices were - ANSWERNever listen to end-user complaints
They did not properly test the software and failed to prevent errors
They denied the errors could exist and failed to repair them.
What was one government agency that was involved with dealing with Therac-25
problems? - ANSWERFDA in the USA and Health Protection Branch in Canada
Why is the Therac report of great importance to programmers - ANSWERBad
software kills people
, The Therac programmers engaged in several practices that either failed to prevent
errors - ANSWERPoor documentation. They did not listen to the end-user.
Insufficient testing
True or False? Replacement of a hardware lockout in a computer-controlled machine
by software will always result in faulty machine operation. - ANSWERFalse. We
need to verify the new hardware is compatible with the software. If the hardware is
compatible, the only limitation is the implementation of the software.
Imperative Programming - ANSWERBy definition, an imperative language tells the
computer what to do
Declarative Programming - ANSWERState what we want without telling the machine
how to do it.
OOP - ANSWERState what we want in the form of objects
What are the three programming paradigms - ANSWERImperative, Declarative,
Object-Oriented
What is one advantage declarative programming languages have over imperative
programming languages? - ANSWERa) declarative programming languages will
figure out how to do the task by themselves as opposed to imperative programming
languages that would have to program how to do the task.
b) It hides the machine. Instead of deciding how to do something, the programmer
can focus on what they want done
c) Declarative languages let go of memory constrain
Give an example of a programming situation in which the C programming language
would be a language of choice? - ANSWERWhen the program needs to be in real-
time
Programming operating systems
Why is the C/C++/Java programming language a poor choice for programming
scientific applications? - ANSWERcomplex arithmetic is poorly supported - no
complex arithmetic
Why should C/Java not be used to write business programs? - ANSWERC/Java
does not have precise decimal arithmetic
Why is Java not the best choice of programming language for business programs? -
ANSWERIt does not support decimal arithmetic. COBOL does decimal arithmetic
Why contrary to all too frequently popular opinion, are Fortran, Cobol and Prolog not
"dead languages" despite their age?( - ANSWERBecause they do their job well. A
language that does something well will endure.
Because they do exactly what they are designed to do and they do it well
