swift 笔记

func Qprint<T>(_ message: T,
            file: String = #file,
            method: String = #function,
            line: Int = #line)
{
    print("[\(line)]-[\((file as NSString).lastPathComponent)]-\(method):\n\(message)\n")
}

字符串操作

///去掉字符串里面所有的某个字符
///- Parameter str:  字符串
///- Parameter c:  要去掉的字符
func deleteCharacterAtString(_ str:String, deleteCharacter c: Character) -> String {
    var newStr = ""
    _ = str.characters.prefix { (i: Character) -> Bool in
        guard i == c else {
          newStr += String(i)
            return true
        }
        return true
    } 
    return newStr
}

let name = "Hello World good"
Qprint(deleteCharacterAtString(name, deleteCharacter: " "))
//打印：
[57]-[ViewController.swift]-viewDidLoad():
HelloWorldgood

 let firstSpace = name.characters.index(of: " ")!
 let firstName =  String(name.characters.prefix(upTo: firstSpace)) //在...之前的字符串
 Qprint(firstName)
//打印：
[55]-[ViewController.swift]-viewDidLoad():
Hello World

//从 xxx 开始到字符串结束
let last = String(name.characters.suffix(from: firstSpace))

符号

    let w  =   "A"..."Z" //ClosedRange 不可数的闭区间
        Qprint(w)
        if  w ~= "C" {
            print("C在A到Z的范围内")
        }

for in

     var array  = Array<Any>()
        for i in 0...100 where i%2 == 0 {
            array.append(i)
        }
        Qprint(array)
//打印
[68]-[ViewController.swift]-viewDidLoad():
[0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100]