Xcode报错：无法将'[String]'转换为预期的'String'类型求解决

错误原因 #

你遇到的报错是因为Question结构体的answers属性被定义为String类型，但创建quiz数组里的Question实例时，传入的是字符串数组（比如["Heart", "Skin", "Large Intestine"]），类型不匹配导致编译器报错。

修复步骤 #

• 将Question结构体中answers的类型改为[String]（字符串数组），匹配多选答案的需求
• 同步更新初始化器init的a参数类型为[String]

修改后的完整代码 #

调整后的Question结构体

import Foundation

struct Question {
    let text : String
    // 改为字符串数组类型，适配多选答案
    let answers : [String]
    let rightAnswer: String

    // 初始化器参数a的类型同步改为[String]
    init(q: String, a: [String], correctAnswer: String) {
        text = q
        answers = a
        rightAnswer = correctAnswer
    }
}

原quiz数组无需修改（传入的a参数已为数组类型）

let quiz = [
    Question(q: "Which is the largest organ in the human body?", a: ["Heart", "Skin", "Large Intestine"], correctAnswer: "Skin"),
    Question(q: "Five dollars is worth how many nickels?", a: ["25", "50", "100"], correctAnswer: "100"),
    Question(q: "What do the letters in the GMT time zone stand for?", a: ["Global Meridian Time", "Greenwich Mean Time", "General Median Time"], correctAnswer: "Greenwich Mean Time"),
    Question(q: "What is the French word for 'hat'?", a: ["Chapeau", "Écharpe", "Bonnet"], correctAnswer: "Chapeau"),
    Question(q: "In past times, what would a gentleman keep in his fob pocket?", a: ["Notebook", "Handkerchief", "Watch"], correctAnswer: "Watch"),
    Question(q: "How would one say goodbye in Spanish?", a: ["Au Revoir", "Adiós", "Salir"], correctAnswer: "Adiós"),
    Question(q: "Which of these colours is NOT featured in the logo for Google?", a: ["Green", "Orange", "Blue"], correctAnswer: "Orange"),
    Question(q: "What alcoholic drink is made from molasses?", a: ["Rum", "Whisky", "Gin"], correctAnswer: "Rum"),
    Question(q: "What type of animal was Harambe?", a: ["Panda", "Gorilla", "Crocodile"], correctAnswer: "Gorilla"),
    Question(q: "Where is Tasmania located?", a: ["Indonesia", "Australia", "Scotland"], correctAnswer: "Australia")
]

内容的提问来源于stack exchange，提问作者D.K Shivashaant