1
//常量 let pi=3.33
//变量 var ene=100
var length = 10, width = 20, height = 30
var age：Int = 24 //为变量age设置整型的数据类型
let isEnemy = false
var emptyString2 = String()
emptyString2.isEmpty
2
print(str)
print(“我的名字是(name)，今年(age)岁了。”)
(name)
print(“我的名字是”+name+”，今年”+age+”岁了。”)
if(score>60)
{
}
字符串拼接：let FullName = firstName + ” “+ “Lee” //结果为：Jerry
Lee
3 整数处理
1 var intNumber = 30
2 intNumber.distance(to：40) //获得两个数据的差值，结
果：10
3 intNumber.advanced(by：20) //将整数增加20，结果：50
4 number.isLess(than：-9.0)
5 number.multiply(by：2)
4 字符串比较
if(passwordFromUser == passwordFromDb)
{
}
字符串开头结尾:
print(userType1.hasPrefix(“京东”)) //true
print(userType2.hasSuffix(“买家”)) //true
5 字符串截取和替换
1 var hello = “Hello, Swift！”
2 hello.substring(from：hello.index(hello.startIndex,
offsetBy：7)) //Swift！
3 hello.substring(to：hello.index(hello.endIndex,
offsetBy：-8)) //Hello
4 hello.replacingOccurrences(of：“Hello”, with：“Hi”)
//Hi, Swift！
5 hello.remove(at：hello.index(hello.startIndex,
offsetBy：5)) //,
6 print(hello) //Hello Swift！
6 迭代for
1 var num = 0
2 let hello = “15011123451”
3 for temp in hello.characters
4 {
5 if temp == “1”
6 {
7 num += 1
8 }
9 }
10 print(num) //结果为：5
7 元组 字典
let people = (“John”, 33)
1 let people = (name：“John”, age：33)
2 print(“People’s name is (people.name), and age is
(people.age).”)
(people.name)
8
1 let one = 1
2 let minusOne = -one //结果为：-1
3 let plusOne = +one //结果为：1
4 let anotherOne = -minusOne //结果为：1
9 循环： for index in 0 ..<3
1 for index in 0 ..< 3
2 {
3 print(“index is (index)”)
4 }
1 let students = [“Jerry”, “Thomas”, “John”]
2 for student in students {
3 print(“Student name：(student)”)
4 }
1 let scores = [“Jerry”：78, “Thomas”：88, “John”：92]
2 for (student, score) in scores
3 {
4 print(student + ”’ score is (score)”)
5 }
10 fi
3 if (count！= 18 && count！= 15)
4 {
5 print(“错误的身份证号码。”)
6 }
if
else if
else
11 switch
1 let time = 12
2 switch time
3 {
4 case 7：
5 print(“It’s time to get up.”)
6 case 8, 12, 18：
7 print(“It’s time for eating.”)
8 case let x where x>18 && x<=24：
9 print(“Happy time.”)
10 case 1……6：
11 print(“It’s time for rest.”)
12 default：
13 print(“Keep busy.”)
14 }
12 数组
1 let stringArray = Array
2 let floatArray = Float
3 let intArry = [1, 2, 3, 4, 5]
1 let intArry = [1, 2, 3, 4, 5]
2 print(intArry[2]) //结果为：3
1 intArry.isEmpty //判断数组是否为空，结果为：false
2 intArry.count //获得数组中元素的数量，结果为：5
3 intArry.contains(3) //判断数组中是否存在3，结果为：true
1 var intArry = [1, 2, 3, 4, 5]
2 intArry += [6] //intArray的元素：[1, 2, 3, 4, 5, 6]
3 intArry.append(7) //intArray的元素：[1, 2, 3, 4, 5, 6, 7]
4 intArry.insert(100, at：2) // intArray的元素：[1, 2, 100,3, 4, 5, 6, 7]
1 intArry.removeFirst() // intArray的元素：[2, 9, 8, 8, 8,6, 7]
2 intArry.removeLast() // intArray的元素：[2, 9, 8, 8, 8,6]
3 intArry.remove(at：2) // intArray的元素：[2, 9, 8, 8,6]
4 intArry.removeSubrange(Range(1..<3)) // intArray的元素：[2, 8, 6]
5 intArry.removeAll() // intArray的元素：[]
13 排序： intArray.sort()
intArry.sort(isOrderedBefore：>)
字典排序
1 var userList = [(name：” Thomas”, age：20), (name：”John”, age：32), (name：” Bill”, age：28)]
2 userList.sort(isOrderedBefore：{1.name})
14 zip
2 let range = 2..
4 {
5 print(“(index)：(value)”)
6 }
1 var diallingCodes1 = Dictionary
2 var diallingCodes2 = [“010”：”北京”, “021”：”上海”,“0592”：”厦门”]
字典更新
diallingCodes.updateValue(“厦门”, forKey：“0592”)
删除值
1 diallingCodes[“020”] = nil
2 diallingCodes.removeValue(forKey：“020”)