TIFR CSE 2011 | Part B | Question: 32

Question

Various parameter passing mechanisms have been in used in different programming languages. Which of the following statements is true?

• A. Call by value result is used in language Ada.
• B. Call by value result is the same as call by name.
• C. Call by value is the most robust.
• D. Call by reference is the same as call by name.
• E. Call by name is the most efficient.

Comments

Refer:

https://gateoverflow.in/270/parameter-passing-technique

Answer 1

e. Call by name is the most efficient.

http://stackoverflow.com/questions/838079/what-is-pass-by-name-and-how-does-it-work-exactly

Comments

Hello zambus.

I didn't find any reason in the link you provided , that supports the argument of option (e).

Explain in detail.

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What is meant by effiiciency here?

Call by name re-evaluates an expression at each occurrence. How is that efficient?

The memoized version of call by name, which is "call by need" is more effective, clearly.

 

Option A is a straight fact, it should be the answer.

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yes, correct. Thats the best way to answer in objective examination. But while preparing it is good to reason out why each option is right/wrong.

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Yes, Arjun sir, I try to reason out each option while preparing ^_^

Answer 2

I accept the fact that option A is right. But can anyone please tell why option B isn't correct. 
Let a = 3; If we call by value i.e. 3, it's fine & if we call by name i.e. 'a', it is again 3.
It seems to be correct both ways.  :)