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-rw-r--r--swift.html.markdown23
1 files changed, 21 insertions, 2 deletions
diff --git a/swift.html.markdown b/swift.html.markdown
index a39bc1d6..df9c5092 100644
--- a/swift.html.markdown
+++ b/swift.html.markdown
@@ -149,6 +149,14 @@ var explicitEmptyMutableDictionary: [String: Float] = [:] // same as above
// MARK: Control Flow
//
+// Condition statements support "where" clauses, which can be used
+// to help provide conditions on optional values.
+// Both the assignment and the "where" clause must pass.
+let someNumber = Optional<Int>(7)
+if let num = someNumber where num > 3 {
+ print("num is greater than 3")
+}
+
// for loop (array)
let myArray = [1, 1, 2, 3, 5]
for value in myArray {
@@ -198,7 +206,6 @@ default: // required (in order to cover all possible input)
let vegetableComment = "Everything tastes good in soup."
}
-
//
// MARK: Functions
//
@@ -240,7 +247,7 @@ let (_, price1, _) = pricesTuple // price1 == 3.69
print(price1 == pricesTuple.1) // true
print("Gas price: \(price)")
-// Named tuple params
+// Labeled/named tuple params
func getGasPrices2() -> (lowestPrice: Double, highestPrice: Double, midPrice: Double) {
return (1.77, 37.70, 7.37)
}
@@ -250,6 +257,18 @@ let (_, price3, _) = pricesTuple2
print(pricesTuple2.highestPrice == pricesTuple2.1) // true
print("Highest gas price: \(pricesTuple2.highestPrice)")
+// guard statements
+func testGuard() {
+ // guards provide early exits or breaks, placing the error handler code near the conditions.
+ // it places variables it declares in the same scope as the guard statement.
+ guard let aNumber = Optional<Int>(7) else {
+ return
+ }
+
+ print("number is \(aNumber)")
+}
+testGuard()
+
// Variadic Args
func setup(numbers: Int...) {
// its an array