Swift 中的subscript下标语法

subscript的简单使用

struct Person {
    private var array: [String] = ["swift", "ios"]
    
    subscript(index: Int) -> String {
        set(new_value) {
            print("set - \(index) - " + new_value)
        }
        
        get {
            print("get")
            return "apple"
        }
    }
}

var person = Person()

person[1] = "hello" //set - 1 - hello
person[4] //get
print(person[4]) //get   apple

struct Person {
    private var array: [String] = ["swift", "ios", "swiftui"]
    
    subscript(index: Int) -> String {
        
        set(new_value) {
            array.insert(new_value, at: index)
        }
        
        get {
            
            return array[index]
        }
    }
}

var person = Person()

person[1] = "apple"
print(person[1]) //apple