NPTEL Software Testing Assignment 8 Answer 2022

 

Week 8 : Assignment 8

Due date: 2022-09-21, 23:59 IST.

Assignment not submitted

1 point

Consider the regular expression (a+b)⋅(a+b)∗$(a+b)·(a+b)\ast$ over the alphabet Σ={a,b}$\Sigma =\{a,b\}$. Which of the following options represents a list of words generated by this regular expression?

ab,a,aab.$ab,a,aab.$

abab,babab.$abab,babab.$

aaa,bbb.$aaa,bbb.$

 All of the above.

1 point

For the same regular expression (a+b)⋅(a+b)∗$(a+b)·(a+b)\ast$ , which of the following options represents the language corresponding to the regular expression?

The language is the set of all words over a$a$ and b$b$ that have at least one a$a$ and at least one b$b$ in them.

The language is the set of all words over a$a$ and b$b$ that have at least one a$a$ or at least one b$b$ in them.

1 point

While parsing a program to extract syntactic information, which of the following defines how characters form tokens?

 Regular expressions.

 Context-free grammars.

 Context-sensitive grammars.

 The normal form of the grammar.

1 point

Consider the context-free grammar given by G=(N,T,P,S)$G=(N,T,P,S)$ where N={S,X},T={a,b},P={S→aXb,X→ab}$N=\{S,X\},T=\{a,b\},P=\{S\to aXb,X\to ab\}$. Which of the following is the language generated by this grammar?

The language generated by G$G$ is {w|w=aabb}.$\{w|w=aabb\}.$

The language generated by G$G$ is {w|w$\{w|w$ is of the form anbn,n≥1}$a^n{b}^n,n\ge 1\}$

1 point

State yes or no: Is the ground string in mutation testing the same as the program under test?

 Yes.

 No.

1 point

Which of the following is a mutant that can be killed by any test case?

 Dead mutant.

 Equivalent mutant.

 Trivial mutant.

 Idempotent mutant.

1 point

Suppose a decision statement like if (x < 0 && z == 5) is mutated to get if (x > 0 && z == 5) then it is an example of which kind of mutation operator?

 Replacing a logical operator.

 Replacing a relational operator.

 Replacing a decision statement.

 Replacing a condition statement.

1 point

As per the lectures, replacing a particular assignment statement with a statement like failOnZero() is an example of a mutation operator applied at which of the levels in testing?

 Program level.

 Integration level.

 Statement level.

 De-bugging level.

1 point

A programmer decides to save time and apply two or three mutation operators together to increase the chances of finding many errors together. Is this considered to be a useful strategy in mutation testing?

 Yes, it will find many errors early.

 No, mutation operators work best when applied one at a time.

1 point

State true or false: Mutation testing can be used to show that a program behaves identically when a particular operation is replaced or removed.

 True.

 False.

You may submit any number of times before the due date. The final submission will be considered for grading.

1. Answer: d) All of the above.

2. Answer: b) The language is the set of all words over a and b that have at least one a or at least one b in them.

3. Answer: a) Regular expressions

4. Answer: a) The language generated by G is {w|w=aabb}.

5. Answer: a) Yes.

6. Answer: c) Trivial mutant.

7. Answer: b) Replacing a relational operator.

8. Answer: a)

9. Answer: b) No, mutation operators work best when applied one at a time.

10. Answer: b) False.