无法分配给属性：“detailDic”是一个“let”常量

Question

我的代码有问题，它告诉我“无法分配给属性：‘detailDic’是一个‘let’常量” 我的构建失败了

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "detail" {
            if let indexPath = self.tableView.indexPathForSelectedRow {
                let dic = cities[indexPath.row]
                let detailVC = segue.destination as! DetailViewController
                detailVC.detailDic = dic
                
                
            }
        }
    }

我试过这个并得到这个错误“运算符'=='的结果未使用”并且它运行但它会崩溃

    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "detail" {
            if let indexPath = self.tableView.indexPathForSelectedRow {
                let dic = cities[indexPath.row]
                let detailVC = segue.destination as! DetailViewController
                detailVC.detailDic == dic
                
                
            }
        }
    }

Answer 1

我发现了我的问题

我用过

let detailDic = [String:String]()

大多数是

var detailDic = [String:String]()