Single line if statement in Swift

In Swift the braces aren't optional like they were in Objective-C (C). The parens on the other hand are optional. Examples:

Valid Swift:

if someCondition {
    // stuff
}

if (someCondition) {
    // stuff
}

Invalid Swift:

if someCondition 
    // one liner

if (someCondition)
    // one liner

This design decision eliminates an entire class of bugs that can come from improperly using an if statement without braces like the following case, where it might not always be clear that something's value will be changed conditionally, but somethingElse's value will change every time.

Bool something = true
Bool somethingElse = true

if (anUnrelatedCondition) 
    something = false
    somethingElse = false

print something // outputs true
print somethingElse // outputs false

Well as the other guys also explained that braces are a must in swift. But for simplicity one can always do something like:

let a = -5

// if the condition is true then doThis() gets called else doThat() gets called
a >= 0 ? doThis(): doThat()

func doThis() {
    println("Do This")
}

func doThat() {
    println("Do That")
}