Thomas Scott
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Multiple choice quiz for exam two.

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Thomas Scott
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Exam 2

Question 1 of 18

1

Which of the following is NOT a top-down parsing?

Select one of the following:

  • Recursive descent parsing

  • Backtracking

  • LL(1) parsing

  • None of these

Explanation

Question 2 of 18

1

Which of the following is true for parser generator

Select one of the following:

  • The input of a parser generator is a token stream

  • The output of a parser generator is abstract syntax tree(AST)

  • CFG of a programming language is part of the input to a parser generator.

  • Flex is a parser generator

Explanation

Question 3 of 18

1

Which of the follwoing is NOT true for parser?

i. The parser is to process a token stream
ii. One of the major responsibilities of parser is to detect syntax errors.
iii. The output of parser is an abstract syntax tree.

Select one of the following:

  • i

  • i, ii

  • i, ii, iii

  • ii, iii

  • iii

  • None of the above.

Explanation

Question 4 of 18

1

Grammar that produce more than one parse tree for same sentence:

Select one of the following:

  • is ambiguous

  • is unambiguous

  • has syntax errors

  • is not LL(1) grammar

Explanation

Question 5 of 18

1

Which of the following is WRONG

Select one of the following:

  • A CFG grammar is said to be ambiguous if for a sentence, there is a leftmost derivation and a rightmost derivation

  • A DFG grammar is said to be ambiguous if for a sentence, there are two leftmost derivations.

  • A CFG grammar is said to be ambiguous if for a sentence, there are two rightmost derivations.

  • A CFG grammar is said to be ambiguous if for a sentence, there are two different parse tree representations.

Explanation

Question 6 of 18

1

The context free grammar S -> SS | 0S1 | 1S0| ε generates.

Select one of the following:

  • Equal number of 0's and 1's

  • Unequal number of 0's and 1's

  • Number of 0's followed by any number of 1's

  • None of the above.

Explanation

Question 7 of 18

1

Which of the following is a Tiger program with syntax errors?

Select one of the following:

  • 1

  • "1"

  • x = 5

  • var x: int := 5

  • All of the above

Explanation

Question 8 of 18

1

Which of the following is a Tiger program without syntax errors?

Select one of the following:

  • (1, 2, 3)

  • (1; 2; 3;)

  • (1; 2; 3)

  • (1, 2, 3,)

  • None of the above

Explanation

Question 9 of 18

1

Which of the following is a Tiger expression with syntax errors?

Select one of the following:

  • a(1)

  • b[1]

  • c[2] of 3

  • (10)

  • NONE of the above

Explanation

Question 10 of 18

1

Which of the following derivations does a LL(1) parser use while parsing an input string? The input is assumed to be scanned in left to right order?

Select one of the following:

  • Leftmost derivation

  • Rightmost derivation

  • None of the above

Explanation

Question 11 of 18

1

Assume X (terminal or non-terminal) is the top symbol in the stack, and c is the next symbol in the input in LL(1) parsing, which of the following indicates a syntax error?

i. x is any terminal other than c
ii. x is a non-terminal, but the cell M[X,c] in the parsing table is empty
iii. x is any non-terminal other than c
iv. x is a non-terminal, but the cell M[X,c] in the parsing table is not empty

Select one of the following:

  • i

  • i and iii

  • i, ii, iii, and iv

  • None of the above

Explanation

Question 12 of 18

1

Assume FIRST(A) = {b, c, d, ε} for a non-terminal A, what's the result of FIRST(eAf) where e and f are terminals?

Select one of the following:

  • {b, c, d, e}

  • {b, c, d}

  • {e, f}

  • {e}

Explanation

Question 13 of 18

1

Assume FIRST(A) ={b, c, d, ε} for a non-terminal A, what's the result of FIRST(Ae) where e is a terminal?

Select one of the following:

  • {b, c , d, e}

  • {b, c, d}

  • {e}

  • {b, c, d, e, ε}

Explanation

Question 14 of 18

1

Assume FIRST(A) ={1, 2, ε}, and FIRST(B) = {b, d} for non- terminal A and B, what's the result of FIRST(AB)?

Select one of the following:

  • {b, d, ε}

  • {1, 2}

  • {b, d, 1, 2}

  • {1, 2, ε}

  • {b, d, 1, 2, ε}

Explanation

Question 15 of 18

1

Assume FIRST(A) ={1, 2, ε}, and FIRST(B) = {b, d} for non- terminal A and B, what's the result of FIRST(BA)?

Select one of the following:

  • {b, d}

  • {1, 2}

  • {b, d, 1, 2}

  • {1, 2, ε}

  • {b, d, 1, 2, ε}

Explanation

Question 16 of 18

1

Assume FIRST(A) ={1, 2, ε}, and FIRST(B) = {b, d, ε} for non- terminal A and B, what's the result of FIRST(BA)?

Select one of the following:

  • {b, d, ε}

  • {1, 2}

  • {b, d, 1, 2}

  • {1, 2, ε}

  • {b, d, 1, 2, ε}

Explanation

Question 17 of 18

1

Assume FOLLOW(A) ={b, d}, FIRST(B) = {1, 2}, for non-terminal A and B, which of the following statements is correct for a production: A-> ABgh where g and h are terminals?

Select one of the following:

  • FOLLOW(B) contains g

  • FOLLOW(B) contains h

  • FOLLOW(B) contains both g and h

  • g and h are not in FOLLOW(B)

  • FOLLOW(B) contains b, and d

Explanation

Question 18 of 18

1

Assume FOLLOW(A) ={b, d}, FIRST(B) = {1, 2, ε}, for non-terminal A and B, which of the following statements is correct for a production: A-> ACB where C is a non-terminal?

Select one of the following:

  • FOLLOW(C) contains {1, 2, ε}

  • FOLLOW(C) contains {b, d}

  • FOLLOW(C) contains {1, 2, b, d, ε}

  • FOLLOW(C) contains {1, 2, b, d}

Explanation

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