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技術社區[雲棲]
Swift學習之十二：控製流
/*
控製流
for for-in while do-while
*/
let count = 5
for var i = 0; i < count; i++ {
print("\(i)")
}
for i in 0..count {
print("\(i)")
}
let base = 4
let power = 10
var answer = 1
// 使用_來忽略某個值
for _ in 1...power {
answer *= base
}
// 訪問數組
let names = ["Anna", "Alex", "Brian", "Jack"]
for name in names {
println("Hello, \(name)")
}
// 訪問字典
let numberOfLegs = ["spider" : 8, "ant" : 6, "cat" :４］
for (key, value) in numberOfLegs {
println("\(key)s have \(value) legs")
}
// 循環遍曆字符串
for c in "Hello" {
print(c)
}
var index: Int
for index = 0; index < 4; ++index {
println("Index is \(index)")
}
// while循環
let times = 10
var count = 0
while count < times {
print("\(count++)")
}
// do-while循環
let times = 10
var count = 0
do {
count++
println("\(count)")
} while count < times
// switch 語句在swift中與C和OC中是不同的，在Swift中匹配到一個Case後，不需要添加break,
// 也會在執行完匹配的那一項後自動Break。
let c = "a"
switch c {
case "a" : print("a")
case "b" : print("b")
case "c" : print("c")
default: print("default")
}
// print a
// 範圍匹配
let count = 1_000_000
var msg: String
switch count {
case 0: msg = "no"
case 1...3: msg = "a few"
case 10...99: msg = "lower than one hundred"
case 100...999: msg = "lower than one thousand"
case 1000...9999: msg = ”lower than then thousand“
case 10000...99999: msg = "lower than one million"
default: msg = "no value"
}
最後更新：2017-04-03 07:57:03