Question

只是一个简单的小代码。它会运行，并打印出正确的结果，但我收到错误：Constant＆＃39; soda1＆＃39;推断出类型为＆＃39;（）＆＃39;，这可能是意料之外的。不知道如何解决它。试图编写一个简单的程序来输出一升汽水的价格。

func sodaoffer(type: String, price: Double, size: Double, amount: Double = 1) {
    let priceL = price / (size * amount)
    print("\(type) costs \(priceL) per liter")
}

let soda1 = sodaoffer(type: "Cola", price: 15, size: 1.5)
let soda2 = sodaoffer(type: "Fanta", price: 50, size: 0.5, amount: 4)
let soda3 = sodaoffer(type: "Faxe Kondi", price: 25, size: 2)

Answer 1

您正在为变量分配一个返回（）或Void（这意味着什么）的函数。

尝试返回一些内容：

func makeSodaOfferString(type: String, price: Double, size: Double, amount: Double = 1) -> String {
    let priceL = price / (size * amount)
    return "\(type) costs \(priceL) per liter)"
}

let sodaOffer1 = makeSodaOfferString(type: "Cola", price: 15, size: 1.5)
let sodaOffer2 = makeSodaOfferString(type: "Fanta", price: 50, size: 0.5, amount: 4)
let sodaOffer3 = makeSodaOfferString(type: "Faxe Kondi", price: 25, size: 2)

print(sodaOffer1)
print(sodaOffer2)
print(sodaOffer3)

Constant＆＃s; soda1＆＃39;推断出类型为＆＃39;（）＆＃39;，这可能是意料之外的

1 个答案: