前端之家收集整理的这篇文章主要介绍了
swift 基础笔记七(for循环),
前端之家小编觉得挺不错的,现在分享给大家,也给大家做个参考。
- //: Playground - noun: a place where people can play
-
- import UIKit
-
- // for 循环
-
- //你可以使用for-in循环来遍历一个集合里面的所有元素,例如由数字表示的区间、数组中的元素、字符串中的字符。
-
-
- for index in 1...5{
- println(index);
- }
-
- //如果你不需要知道区间内每一项的值,你可以使用下划线(_)替代变量名来忽略对值的访问
- var count = 3;
- var one = 1;
- var two = 2;
- for _ in 1...count{
- one *= two
- }
-
- // 遍历数组
-
- var arr1 = ["E","n","d","a"];
- for name in arr1{
- println(name);
- }
-
- // key + value
- var arr2 = [1:"E",2:"n",3:"d",4:"a"];
- for (key,value) in arr2{
- println("\(key)==>\(value)")
- }
-
-
- // 遍历字符串
-
- var names = "MyNameisEnda";
-
- for name in names{
- println("\(name)");
- }
-
- // for 条件递增
- for var index = 0;index<3;++index{
- println(index);
- }