Syntax Directed Translation MCQ Quiz in मल्याळम - Objective Question with Answer for Syntax Directed Translation - സൗജന്യ PDF ഡൗൺലോഡ് ചെയ്യുക
Last updated on Apr 12, 2025
Latest Syntax Directed Translation MCQ Objective Questions
Top Syntax Directed Translation MCQ Objective Questions
Syntax Directed Translation Question 1:
Consider the grammar G:
(assume Bottom up parsing)
S → 0{ printf(“a”) }A
A → 1{ printf(“b”) }B
A → 2{ printf(“c”) }
A → ϵ { printf(“-“) }
B → 3 { printf(“b”) }A
B → ϵ { printf(“a”) }
What will be the input for the output “cbbbba”?
Answer (Detailed Solution Below)
Syntax Directed Translation Question 1 Detailed Solution
Answer: Option 1
Explanation:
for Bottom-up parsing the Rules associated with a production executed at the time of reduction.
Option 4: 011332
This Option is not correct, since the 011332 can not be generated from the given Grammar.
Option 3: 033112
This option is also not correct, since the 033112 can not be generated from the given Grammar.
Option 2: 031312
This option is also not correct, since the 031312 can not be generated from the given Grammar.
Option 1: 013132
This Option is the correct answer Since 013132 can generate the output "cbbbba":
Syntax Directed Translation Question 2:
Consider the following Syntax directed translation (SDT)
S → TR { printf(+) }
R → +T { printf(*) } R { printf(+) } | ε { printf(*) }
T → num { printf(+) }
The input to this SDT is 2 + 3 + 4 + 5.
What will be the length of the longest Consecutive Repeating sequence in output?
Answer (Detailed Solution Below) 4
Syntax Directed Translation Question 2 Detailed Solution
Concept: To analyze the output from the SDT, first we need to draw the parse tree or annotated parse tree for the given input string. Then, we can traverse through that parse tree and find the output in an efficient way by traversing the tree from left to right.
First draw the parse tree for the given string from the given SDT i.e,
we got the output + + * + * + * * + + + +.
Hence, the length of the longest Consecutive Repeating sequence will be 4, and the longest Consecutive Repeating character is '+'.
Syntax Directed Translation Question 3:
Consider the following grammar (that admits a series of declarations, followed by expressions) and the associated syntax directed translation (SDT) actions, given as pseudo-code:
P → D* E*
D → int ID {record that ID.lexeme is of type int}
D → bool ID { record that ID.lexeme is of type bool}
E → E1 + E2 {check that E1.type = E2.type = int; set E.type := int}
E → !E1 {check that E1.type = bool; set E.type := bool}
E → ID {set E.type := int}
With respect to the above grammar; which one of the following choices is not correct?
Answer (Detailed Solution Below)
Syntax Directed Translation Question 3 Detailed Solution
Explanation:
Option 1: The actions will lead to an infinite loop.
This statement is not correct.
Option 2: The actions can be used to correctly type-check any syntactically correct program.
This statement is not correct. Because These SDT actions can not type-check boolean expressions or float expressions.
for example :
float a = 3.46;
bool b = 0,c;
c = a + b;
Option 3: The actions can be used to type-check syntactically correct boolean variable declarations and boolean expressions.
This statement is not correct. Because the SDT actions can not be used to correctly type check boolean expressions.
for example :
bool a = 0;
bool b = 1;
bool c = a + b;
Option 4: The actions can be used to type-check syntactically correct integer variable declarations and integer expressions.
This statement is Correct. Because These SDT actions can be used to correctly type check both integer variables and integer expressions as well.
Syntax Directed Translation Question 4:
Convert the pre-fix expression to in-fix
--*+ABC*DE+FG
Answer (Detailed Solution Below)
Syntax Directed Translation Question 4 Detailed Solution
Option 4:
(A+B)*C - (D*E)-(F+G)
+AB*C - (D*E)-(F+G)
+AB*C - *DE - (F+G)
+AB*C - *DE - +FG
*+ABC - *DE - +FG
-*+ABC*DE - +FG
--*+ABC*DE+FG
Syntax Directed Translation Question 5:
Consider the following attributed grammar
S → A + B { S.val = A.val + B.val }
A → id { A.val = id.val }
B → id { B.val = id.val }
Answer (Detailed Solution Below)
Syntax Directed Translation Question 5 Detailed Solution
Synthesized attributes:
A Synthesized attribute is an attribute of the non-terminal on the left-hand side of a production. Synthesized attributes represent information that is being passed up the parse tree. The attribute can take value only from its children.
S-attributed SDT
If an SDT uses only synthesized attributes, it is called as S-attributed SDT.
Example:
S → A + B { S.val = A.val + B.val }
A → id { A.val = id.val }
B → id { B.val = id.val }
Inherited attributes:
An attribute of a nonterminal on the right-hand side of a production is called an inherited attribute. The attribute can take value either from its parent or from its siblings.
L-attributed SDT
If an SDT uses both synthesized attributes and inherited attributes with a restriction that inherited attribute can inherit values from left siblings only, it is called as L-attributed SDT.
Therefore, every S-attributed definition is L-attributed but vice versa is not true.
Hence SDT is L-attribute and S-attributed
Syntax Directed Translation Question 6:
Consider the following grammar and the semantic actions to support the inherited type declaration attributes. Let X1, X2, X3, X4, X5 and X6 be the placeholders for the non-terminals D, T, L or L1 in the following table:
|
Production rule |
Semantic action |
|
D → T L |
X1.type = X2.type |
|
T → int |
T.type = int |
|
T → float |
T.type = float |
|
L → L1, id |
X3.type = X4.type addType(id.entry, X5.type) |
|
L → id |
addType(id.entry, X6.type) |
Which one of the following are the appropriate choices for X1, X2, X3 and X4?
Answer (Detailed Solution Below)
Syntax Directed Translation Question 6 Detailed Solution
Concepts:
Synthesized attributes:
A Synthesized attribute is an attribute of the non-terminal on the left-hand side of a production. Synthesized attributes represent information that is being passed up the parse tree. The attribute can take value only from its children.
S-attributed SDT
If an SDT uses only synthesized attributes, it is called as S-attributed SDT.
Inherited attributes:
An attribute of a nonterminal on the right-hand side of a production is called an inherited attribute. The attribute can take value either from its parent or from its siblings.
L-attributed SDT
If an SDT uses both synthesized attributes and inherited attributes with a restriction that inherited attribute can inherit values from left siblings only, it is called as L-attributed SDT.
In SDT:
D → T L {X1.type = X2.type}
L.type = T.type (Inherited attributed )
∴ X1 = L and X2 = T
T can be int or float
In SDT:
L → L1, id {X3.type = X4.type}
L1.type = L.type (Inherited attributed)
∴ X3 = L1 and X4 = L
Hence option 1 is correct.
Syntax Directed Translation Question 7:
Let SDT be
S → BC {B.val = C.val}
The above SDT is
Answer (Detailed Solution Below)
Syntax Directed Translation Question 7 Detailed Solution
Synthesized attributes:
A Synthesized attribute is an attribute of the non-terminal on the left-hand side of a production. Synthesized attributes represent information that is being passed up the parse tree. The attribute can take value only from its children.
S-attributed SDT
If an SDT uses only synthesized attributes, it is called as S-attributed SDT.
Example: S → BC
S.val = B.val
S.val = C.val
But B.val = C.val is not a S-attributed SDT
Inherited attributes:
An attribute of a nonterminal on the right-hand side of a production is called an inherited attribute. The attribute can take value either from its parent or from its siblings.
L-attributed SDT
If an SDT uses both synthesized attributes and inherited attributes with a restriction that inherited attribute can inherit values from left siblings only, it is called as L-attributed SDT.
Example: S → BC
S.val = B.val
S.val = C.val
Also
C.val = B.val
C.val = S.val
B.val = S.val
Therefore B.val = C.val is not a L-attributed SDT
Hence is neither S-attributed SDT nor L-attributed SDT
Syntax Directed Translation Question 8:
Consider a Grammar E → E + n|E x n|n for a sentence n + n x n, the handles in the right-sentential form of the reduction are?
Answer (Detailed Solution Below)
Syntax Directed Translation Question 8 Detailed Solution
The correct answer is n, E + n and E x n
EXPLANATION:
In the given grammar E → E + n | E x n | n, let's consider the sentence n + n x n.
- The right-sentential form during the reduction process will be as follows:
- n + n x n (Start with the original sentence)
- E + n x n (Apply the reduction E → n)
- E x n (Apply the reduction E → E + n)
- E (Apply the reduction E → E x n)
Therefore, the correct option is: 4) n, E + n, and E x n
Syntax Directed Translation Question 9:
Consider the following SDT
L -> E
E -> { printf("+") } E1 + T | T
T -> { printf("*") } | T1 * F | F
F -> (E)
F -> digit { printf(digit.val)}
Which of the following is true about the above SDT?
Answer (Detailed Solution Below)
Syntax Directed Translation Question 9 Detailed Solution
The correct answer is option 3
Explanation:
According to the given SDT is used to convert infix to prefix expression
Example:
Infix expression : 5+2*7
So, it gives the prefix expression +5*27
Syntax Directed Translation Question 10:
Consider the following SDT to generate three address code of expression Statement ( E ) by using the following grammar productions where "place" is an attribute that gives the name of the variable that will hold the value of E and code is an attribute that gives 3-address code at every place and newtemp() function generates new temporary variable on every function call. gen() function generates the output intermediate code.
|
PRODUCTION |
SEMANTIC RULES |
|
S → id := E |
S.code := E.code || gen(id.place : = E.place) |
|
E → E1 + E2 |
E.place := newtemp(); |
|
E → E1 * E2 |
E.place := newtemp(); |
|
E → - E1 |
E.place := newtemp(); |
|
E →(E1) |
E.place := E1.place; |
|
E → id |
E.place := id.place; E.code := ‘ ’ |
What will be the appropriate expression in place of X and Y for SDT to generate the three Address of Expression { only involving +, *, -, (, ) }.
(uminus stands for unary minus)
Answer (Detailed Solution Below)
Syntax Directed Translation Question 10 Detailed Solution
Explanation:
The Given SDT is supposed to generate 3 address code
E → E1 + E2 /the addition must be assigned to a temp variable So is E.place = newtemp()
And the place values of E1 and E2 must be added and assigned to their place attribute so
So Y: = E1.place + E2.place
And for E → E1 * E2 / X := E1.place * E2.place
Hence Only Option correct is Option 2.
Note:There is no need to generate a temporary variable for E1 and E2 ( in E → E1 + E2 ) because variables E1 and E2 will already exists in the symbol table, we need only to generate temp variable for E and assign the sum of E1 value and E2 value and assign it to E’s place attributes ( where E’s temporary variable is)