GATE1997

Question

What is S1,S2?and how to to decide their scope for variable access?

Procedure A;
  x,y:intger;
   Procedure B;
    x,z:real
    S1
   end B;
   Procedure C;
      i:integer;
       S2
   end C;
end A;

The variables accessible in S1 and S2 are
(A) x of A, y, x of B and z in S1 and x of B, y and i in S2
(B) x of B, y and z in S1 and x of B, i and z in S2
(C) x of B, z and y in S1 and x of A, i and y in S2
(D) None of the above

Comments

S1 and S2 are supposed to be some lines of code which use some variables.

Now S1 is within procedure B. See that x and z are declared in B. So S1 can access x and z of B. Since procedure B is declared inside A so it can also access A's variables x and z. Though "x" can cause ambiguity but there is a way to access it.

See this : https://stackoverflow.com/questions/3882621/how-to-access-outer-block-variable-in-inner-block-when-inner-block-have-same-var

Now S2 is inside C. So it can access i of C and x and y of A because C is itself inside A.

Ans should be: x,z of B & x,y of A,in S1 and x,y of A and i of C in S2

According to geeksforgeeks they aren't considering the chance of using x of A in S1.

So Option C matches.

 

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A similar type here for practice https://gateoverflow.in/93966/gate1988-2xii?#a232342

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@MiNiPanda
You're right.

Actually the question meant the local scoping of the functions. So the correct answer should be C.

Answer 1

Option C

S1--> x  and z of B and  y of A accessible here but due to ambiguity  x of A can't be access

S2-->x and y of A  and i of C  can be access here

Comments

sir i really statisfy with your explanation,but u see that option C does not match with your explanation so can be put option D  as correct answer