What is the convention for expressing the conditions in an "if" statement? Parenthesis or not?

Question

Both work and in the "Collections and Control Flow" @Pasan Premaratne (https://teamtreehouse.com/pasan) does both. In the first video...
swift
if weather < 18 {}

But in the last video (FizzBuzz) challenge...
swift
if (i % 3 == 0) && (i % 5 == 0) {}
else if (i % 3) {}

I've altered both to the opposites and it still compiles properly. So, which is the best or the 'right' way?

Martin Wildfeuer · Accepted Answer

Hey there!
the convention with Swift is to not use parentheses with if statements, like in your first example.
swift
if condition {
   ...
}

In the first line of your second example, however, it is not about the parentheses with if statements, but rather about increasing readability with operators:
```swift
if (i % 3 == 0) && (i % 5 == 0) { // Increase readability
} else if (i % 3) { // Not needed, like example 1
}
```
From Apple Docs: Explicit parenthesis (https://developer.apple.com/library/ios/documentation/Swift/Conceptual/Swift_Programming_Language/BasicOperators.html):
Explicit Parentheses
It is sometimes useful to include parentheses when they are not strictly needed, to make the intention of a complex expression easier to read.
So, to put it short: don't use parentheses for wrapping the condition, but use them whenever it increases readability with complex conditions.
Hope that helps :)

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Jason Anders

Jason Anders

What is the convention for expressing the conditions in an "if" statement? Parenthesis or not?

1 Answer

Martin Wildfeuer

Martin Wildfeuer

Jason Anders

Jason Anders