/*
* 本节内容:
* 1.Bool
* 2.String/Character
* 3.Tuple(*****)
*/
显示和隐式声明Bool类型
let swiftIsCool: Bool = true
let swiftIsHard = false
let value = 10
哪怕只有一行语句, 必须加大括号
必须只能true/false才作为if条件; 非零值不能作为条件
if value == 10 {
print("I think so.")
}
if swiftIsHard {
print("I donot agree with u.")
}
显示和隐式声明字符串和字符
var stringOne = "hello swift"
var stringTwo: String = "hello world"
字符串插值(String Interpolation)
var stringThree = "Merge two string: \(stringOne) and \(stringTwo)"
字符串拼接: "+"
var stringFour: String = "Say hello to "
let stringFive = "Jonny"
let stringReslut = stringFour + stringFive
+=对于字符串来说, 两个字符串拼接好之后, 再赋值给左边变量
mutable: 可变的; NSMutableArray
stringFour += stringFive
字符串和字符的关系: 打印stringFour的所有字符
for character in stringFour.characters {
// character是一个常量
print("stringFour's character is \(character)")
}
字符类型必须显示声明
let oneCharacter: Character = "!"
String(oneCharacter) + stringFour
let chineseChar: Character = "周" let emojiOne: Character = "