更新时间：2017-8-16
一、基础知识笔记
/**
* Swift 4.0 学习
*/
import UIKit
var a = ""
var b = " "
a.isEmpty
b.isEmpty
b.count
var ruo: Character = "其"
let words = "中国人有人人械"
for heword in words {
print("字: ",heword)
}
let a = "便是"
let b = "人间"
let c = "好时节"
var d = a + b + c
let smil = "小明"
d.append(smil)
print("\" \\ \n a \'")
多行字符串
let code = """
<html>
<head>js test</head>
<script>
function changeParaText() {
document.getElementById('p1').innerHTML = "更新后的文字"
}
</script>
<body>
<p id="p1">这是一个swift多行字符串</p>
<button type="button" onclick="changeParaText()">点击按钮更新文字</button>
</body>
</html>
"""
let name = "李白"
let type = "G"
let num = 168
let desc = "长安"
let deTi = "洛阳"
let price = 380
let msg = """
尊敬\(name)的乘客，您已订购\(type)\(num)\(desc)到\(deTi)的往返票，需要支付\(380 * 2)元。
"""
let a = """
海客谈瀛洲
烟涛微茫信难求
越人语天姥
云霞论坛系统好
世博五月延迟成
天台一万八千张
对此欲倒东南倾
"""
索引
a.startIndex
a.endIndex
a.count
a[a.startIndex]
a[a.index(after: a.startIndex)]
a[a.index(before: a.endIndex)]
a[a.index(a.startIndex, offsetBy: 3)]
a[a.index(a.endIndex, offsetBy: -3)]
for index in a.indices {
print(a[index])
}
for b in a {
print(b)
}
插入和删除
var a = "世界尽快头"
a.insert(",", at: a.endIndex)
let b = "难分离李克勤春哥?"
a.insert(contentsOf: b, at: a.endIndex)
//删除 remove
//a.remove(at: a.index(before: a.endIndex))
//删除一个范围
let str = a.index(a.endIndex, offsetBy: -(b.count))
let bRange = str..<a.endIndex
a.removeSubrange(bRange)
let a = "等额本息"
let b = "等额本金!"
let c = "等额"
let d = "!"
//前缀
a.hasPrefix(c)
b.hasPrefix(c)
//后缀
a.hasSuffix(d)
b.hasSuffix(d)
//集合类
/**
* 1.有序可重复的集合: 数组
* 2.无序不重复的集合: Set
* 3.无序可重复，但有键值:Dic
* 4.批量处理集合中的元素，可以使用for in循环
*/
//创建数组
let array = Array(repeating: 1, count: 50)
let intRangeArray = Array(-2...2)
var topLange = ["java", "c", "C++", "Php"]
topLange.count
topLange.isEmpty
//添加元素
topLange.append("OC")
let h5 = ["html","css", "js"]
topLange += h5
//获取元素索引
topLange[7]
//插入
topLange.insert("Swift", at: 4)
//移除
topLange.remove(at: 8)
//高阶操作:求和，连接元素，reduce
//高阶操作: 变形map
//set : 如身份证号、护照
var cardNo:Set = [1,2,3]
var citys: Set = ["shanghai", "beijing","chengdu", "shanghai"]
citys.count
//插入
citys.insert("ShenZhen")
//移除
citys.remove("shanghai")
//是否包含某元素:contains
citys.contains("beijing")
//转换为数组:sorted
let citysArray = citys.sorted()
//集合音的运算:交差并补
var x: Set = [1,2,3,4]
var y: Set = [4,5,6,7,]
//交集
x.intersection(y)
//补集
x.symmetricDifference(y)
//差集
x.subtract(y)
//并集
x.union(y)
//集合间的关系
//相等
let h: Set = [1,2,3]
let i: Set = [3,2,1,4]
h == i
//子集
h.isSubset(of: i)
h.isStrictSubset(of: i)
//父集
i.isSuperset(of: h)
i.isStrictSubset(of: h)
//无交集
let j: Set = ["game","player"]
let k: Set = ["sport", "walking"]
j.isDisjoint(with: k)
//字典
var b:[Int: String]
var airports = ["PVG":"东城国际", "CHU": "成都大酒店","DUB":"大理"]
//计算
airports["SHQ"] = "虹桥机场"
airports["CHU"] = "大边周水"
//获取
airports["SHQ"]
//移除
airports["DUB"] = nil
//循环用元组
//for (key, value) in airports {
// print(key, value)
//}
for value in airports.keys {
print(value)
}
for key in airports.values {
print(key)
}
let codes = [String](airports.keys)
let name = [String](airports.values)
网友评论