我一直在断断续续地寻找这个答案。我使用GKStateMachine，喜欢观察状态变化，想要一种简单的方法来查看类名。我不确定它是iOS 10还是Swift 2.3，但在这种环境下，以下内容正是我想要的:

let state:GKState?
print("Class Name: \(String(state.classForCoder)")

// Output:    
// Class Name: GKState

你可以试试这种方法:

self.classForCoder.description()

Swift 5.1:-

你也可以使用泛型函数获取对象的类名作为字符串

struct GenericFunctions {
 static func className<T>(_ name: T) -> String {
        return "\(name)"
    }

}

使用以下方法调用此函数:-

let name = GenericFunctions.className(ViewController.self)

快乐编码:)

在Swift 4.1和现在的Swift 4.2中:

import Foundation

class SomeClass {
    class InnerClass {
        let foo: Int

        init(foo: Int) {
            self.foo = foo
        }
    }

    let foo: Int

    init(foo: Int) {
        self.foo = foo
    }
}

class AnotherClass : NSObject {
    let foo: Int

    init(foo: Int) {
        self.foo = foo
        super.init()
    }
}

struct SomeStruct {
    let bar: Int

    init(bar: Int) {
        self.bar = bar
    }
}

let c = SomeClass(foo: 42)
let s = SomeStruct(bar: 1337)
let i = SomeClass.InnerClass(foo: 2018)
let a = AnotherClass(foo: 1<<8)

如果你周围没有实例:

String(describing: SomeClass.self) // Result: SomeClass
String(describing: SomeStruct.self) // Result: SomeStruct
String(describing: SomeClass.InnerClass.self) // Result: InnerClass
String(describing: AnotherClass.self) // Result: AnotherClass

如果你有一个实例:

String(describing: type(of: c)) // Result: SomeClass
String(describing: type(of: s)) // Result: SomeStruct
String(describing: type(of: i)) // Result: InnerClass
String(describing: type(of: a)) // Result: AnotherClass

我建议这样的方法(非常Swifty):

// Swift 3
func typeName(_ some: Any) -> String {
    return (some is Any.Type) ? "\(some)" : "\(type(of: some))"
}

// Swift 2
func typeName(some: Any) -> String {
    return (some is Any.Type) ? "\(some)" : "\(some.dynamicType)"
}

它既不使用内省，也不使用手动提取(没有魔法!)

下面是一个演示:

// Swift 3

import class Foundation.NSObject

func typeName(_ some: Any) -> String {
    return (some is Any.Type) ? "\(some)" : "\(type(of: some))"
}

class GenericClass<T> {
    var x: T? = nil
}

protocol Proto1 {
    func f(x: Int) -> Int
}


@objc(ObjCClass1)
class Class1: NSObject, Proto1 {
    func f(x: Int) -> Int {
        return x
    }
}

struct Struct1 {
    var x: Int
}

enum Enum1 {
    case X
}

print(typeName(GenericClass<Int>.self)) // GenericClass<Int>
print(typeName(GenericClass<Int>()))  // GenericClass<Int>

print(typeName(Proto1.self)) // Proto1

print(typeName(Class1.self))   // Class1
print(typeName(Class1())) // Class1
print(typeName(Class1().f)) // (Int) -> Int

print(typeName(Struct1.self)) // Struct1
print(typeName(Struct1(x: 1))) // Struct1
print(typeName(Enum1.self)) // Enum1
print(typeName(Enum1.X)) // Enum1

斯威夫特5:

方式1:

print("Class: \(String(describing: self)), Function: \(#function), line: \(#line)")

输出:

Class: <Test.ViewController: 0x7ffaabc0a3d0>, Function: viewDidLoad(), line: 15

方式2:

print("Class: \(String(describing: type(of: self))), Function: \(#function), line: \(#line)")

输出:

Class: ViewController, Function: viewDidLoad(), line: 16