Swift 循环(for ,while, do..while)
2017-11-10 本文已影响7人
追逐_chase
Swift.png
for循环
- 常见的写法
//传统的写法,已经在Swift 3中移除了额,这种写法是错误的
//for var i = 0; i < 10; i += 1 {
//
// print(i);
//}
//在swift中 for循环 要使用区间,之前的写法不在适用了
//正确的写法
for i in 0..<10 {
print(i);
}
// _代表忽略的意思 区间遍历
for _ in 0..<10 {
print("zaza");
}
var numbers = ["cc","ss","dd"]
for i in 0 ..< numbers.count {
print(numbers[i]);
}
//反向遍历
let testArray = ["1","2","3","4"];
for i in testArray.reversed() {
print(i)
}
//打印结果: 4,3,2,1
while循环
var i = 10;
//条件必须为真才执行
while i > 0 {
i -= 1;
print(i);
}
repeat...while循环 代替 do..while
-
注意 在swift中 do..while循环已经被 repeat...while 代替,原因:do在swift有特殊的含义
do..while.jpg
var i = 5;
repeat{
i += 1;
print(i);
} while i < 10