一愧口、字符串

1、Character 字符類型

let chaA: Character = "好"
let chaB: Character = "B"
let chaC: Character = "\\"

print(chaA, chaB, chaC)

2托嚣、String 類型

let str1 = "Hello word"
var str2 = String()
print(str1)
print(str2)

if str2.isEmpty {
    print("字符串是空的")
}

3、字符串長度計算

print("str1字符串長度：\(str1.count)")

4兢哭、遍歷字符串

for c in str1 {
    print(c)
}

5夫嗓、鏈接字符串

let str3 = "my name is lila"
var str4 = str1 + "," + str3
print(str4)
str4 += "."
print(str4)
str4.append("好開心")
print(str4)

6、字符串的插值

let num10 = 10
let message = "\(num10)*2.5=\(Double(num10)*2.5)"
print(message)

7格式化字符串

let hour = 9
let minute = 10
let seconds = 22
let time = String(format: "%02d:%02d:%02d", hour, minute, seconds)
let time2 = String(format: "%01d:%04d:%03d", hour, minute, seconds)
print(time,time2)

8舍咖、字符串截取

let firstSpace = str4.firstIndex(of: " ") ?? str4.endIndex

let subStr1 = str4[..<firstSpace]
print(subStr1)

let someRange = str4.range(of: "lila")
let subStr3 = str4[someRange!]
print(subStr3)
print(str4[..<someRange!.lowerBound])
print(str4[someRange!.upperBound...])

let someRange3 = str4.range(of: "好開心")
print(str4[..<someRange3!.lowerBound])
print(str4[someRange3!.upperBound...])



let subStr2 = str4.split(separator: " ", maxSplits: 10, omittingEmptySubsequences: true)
print(subStr2)

9谎仲、比較字符串

let name1 = "lili"
let y = "lili"
if y == name1 {
    print("一樣的")
}

10刨仑、比較字符串前綴后綴

let httpStr = "https://swift.com.cn"
if httpStr.hasPrefix("http") {  //前綴
    print("http")
}
if httpStr.hasSuffix("cn") {    //后綴
    print("com")
}

二、數(shù)組

1杉武、定義數(shù)組

//定義一個string類型的數(shù)組
var arr1:Array<String>
var arr2:[String]

2、創(chuàng)建空數(shù)組

var someInts = [Int]()

3飞涂、使用字面量構造數(shù)組

let names:[String] = ["lisa", "haojie", "sande"]
let arr3 = ["haozi", 17] as [Any]
print(arr3)

4祈搜、數(shù)組相加

arr1 = ["老大", "老二"]
arr2 = ["男", "女"]
var arr4 = arr1 + arr2
print(arr4)

5、數(shù)組長度梁呈、遍歷

print(arr4.count)
for name in arr4{
    print(name)
}

6蘸秘、增加刪除

arr4.append("ss")
print(arr4)
arr4.insert("aa", at: 2)
print(arr4)
arr4.remove(at: 0)
print(arr4)
arr4.removeLast()
print(arr4)
arr4.removeFirst()
print(arr4)
arr4.removeAll()
print(arr4)

7、使用下標法修改數(shù)組元素

var arr5 = arr3 + arr2
print(arr5)
arr5[0] = "ssssss"
print(arr5)

三醋虏、字典與集合

1、創(chuàng)建字典

var dic1:Dictionary<String, String> = ["name":"lili","age":"18"]

2毛秘、增加粘舟、替換

var dic2:Dictionary = ["name":"lili","age":18] as [String: Any]
dic2["name"] = "ak47"
print(dic2)

dic2["sex"] = "man"
print(dic2)

3佩研、合并

var dic3 = ["title":"heheheheh"]
for (k,v) in dic3 {
    dic2[k] = v
}
print(dic2)

dic2.removeValue(forKey: "sex")

print(dic2.keys)
print(Array(dic2.keys))
print(dic2.values)
print(Array(dic2.values))