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Swift 条件选择(if Switch),循环结构(三),
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switch
- var i = 0
- switch i {
- case 0:
- print("0")
- case 1:
- print("1")
- default:
- print("default")
- }
不用加上break,Swift的Switch语句会自动在case结尾处加上break,但是在某些情况下,我们可能会希望Switch能同时执行两条case如下:
- var j = 3
- switch j {
- case 0,3:
- print("0,3")
- fallthrough
- case 1:
- print("1")
- default:
- print("default")
- }
-
-
-
-
支持多种数据类型:浮点,布尔,字符串,支持区间运算符例子如下
- var k = 15
- switch i {
- case 0 ... 10:
- break
- case 11 ... 20:
- break
- default:
- break
- }
- let request = (true,"success")
- switch request {
- case (true,"success"):
- print("success")
- break
-
- case (false,"Failed"):
- print("Failed")
- break
-
- default: break
-
- }
支持额外的逻辑判断
- let request1 = (0,"success")
- switch request1 {
- case (0,let state) where state != "success":
- state
- case (let errorCode,_):
- "error code is \(errorCode)"
- }
-
- var string:String = "Hello"
- if string == "Hello"{
- print("YES")
- }else{
- print("NO")
- }
循环for
- // for in
- for var i in 1...5{
- print(i)
- }
- var ii = 0
- while ii < 11
- {
-
- print("while")
- }
- // repeat-while::do-while
- var jj = 0
- repeat{
-
- }while i < 11