CODEWITHSUNDEEP
performanceif-statement
MyNameIsKhan
MyNameIsKhan

Reputation: 2612

If statements with return: Faster to use elseif?

Is it generally better/faster to do:

if (condition) return a
else if (condition2) return b
else return c

or

if (condition) return a
if (condition2) return b
return c

They both do the same thing but I am curious if there are other ramifications that need to be kept in mind when comparing these two snippets

Upvotes: 0

Views: 408

Answers (6)

hatchet - done with SOverflow
hatchet - done with SOverflow

Reputation: 16259

Go with what is most readable and maintainable. You likely won't see any difference between the two versions of code because compilers are usually good at making these sorts of branch optimizations for you. So the resulting compiled code may be essentially the same in both cases. Leave it for the compiler to do this sort of micro optimization.

Upvotes: 1

codecool
codecool

Reputation: 6036

There is no difference in this case but following examples are different:

    if (condition) do work1
    else if (cond2) do work2
    else if (cond3) do work3
    else do work4
    more work

If first condition is true then program will move to "more work" statement and no other conditions are tested, but in following all conditions will be tested even if first condition is true (except else):

    if (condition) do work1
    if (cond2) do work2
    if (cond3) do work3
    else work4

    more work

Thats the only difference and it does not affect speed much unless there are thousands of if statements.

Both have different use cases:

Run first one where you want to stop as soon as a true condition is encountered.

Run second one when you want to test more conditions even after you have found
a true condition.

Upvotes: 0

Joseph Koech
Joseph Koech

Reputation: 23

What ELSE IF means is if the previous IF statement isn’t true, then try 'this' one. From my experience, IF works much faster and is great if you only need to check for one condition. ELSE IF is more ideal for different conditions.

Upvotes: -1

Michael Kohler
Michael Kohler

Reputation: 753

Since there is always the same amount of code executed, it won't make any difference. In terms of readability of the code I strongly suggest to use the "else" version. In this version you directly see (because of the "else") that the first condition is not true in order to execute the else if branch. In the second example you could miss the "return" when reading and be confused why the code checks for several conditions.

Upvotes: 3

Arran
Arran

Reputation: 25056

The difference is negligible/none.

When performance-tuning your code, I'd look elsewhere to be honest.

Upvotes: 1

Kevin
Kevin

Reputation: 2688

Honestly, I tried testing, and found no difference what-so-ever.

I think it's personal preference over anything else, that and the 2nd one is less code to write...

Upvotes: 0

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