typescript - 打字稿：无法获取属性“块”的值：对象为空或未定义

Question

我为有效的电话号码编写代码。但是当我编译项目时，我有以下错误：

1. 无法获取属性“块”的值：对象为空或未定义；

2. 命令的输出 ""C:\Program Files (x86)\Microsoft SDKs\TypeScript\tsc" "C:..\Scripts\MyScripts\TS\BuildPhone.ts" "C:..\Scripts\MyScripts\TS\ProductsViewModel .ts" "C:..\Scripts\MyScripts\TS\helloWorld.ts"" 代码为 1。

   // Interface
   interface IPhoneBuild
   {
       showPhone(): string;
       checkPhone(): boolean;
   }
   
   class Phone
   {
       Code: string;
       Number: string;
       Fax: boolean;
   }
   
   // Module
   module Phones
   {
       // Class
       export class PhoneBuild implements IPhoneBuild
       {
           private phone: Phone;
           private codes: string[];
   
           // Constructor
           constructor(public Number: string, public Code: string, public Codes: string[])
           {
               this.phone = this.buildPhone(Number, Code);
               this.codes = Codes;
           }
   
           //Private Methods
           private clearPhone(public reg: string)
           {
               var re = /\W/g;
               return reg.replace(re, "");
           }
   
           private buildPhone(public num: string, public code: string)
           {
               var p: Phone = { Code: "", Number: "", Fax: false };
   
               num = this.clearPhone(num);
   
               if (num.length == 6)
               {
                   p = { Code: code, Fax: false, Number: num };
               }
   
               if (num.length == 11)
               {
                   p = { Code: num.substring(0, 4), Fax: false, Number: num.substring(4)};
               }
   
               return p;
           }
   
           // Instance member
           public showPhone()
           {
               return this.phone.Code + this.phone.Number;
           }
   
           public checkPhone()
           {
               return this.phone.Number.length != 7 || this.phone.Code.length == 0;
           }
       }
   }
   

你有什么想法？我需要帮助。

我找到了解决方法：在方法中的属性中删除“公共”：buildPhone 和 clearPhone。

Answer 1

您不能将成员的参数声明function为公共的。这仅对用作以下简写的构造函数有效：

• 声明成员变量
• 还将输入参数分配给成员变量

Answer 2

我已经快速整理了您的代码。

在您使用public或private在构造函数中，您可以避免从参数映射到类上的属性，因为 TypeScript 编译器会自动为您完成。

您的方法参数不需要这些访问修饰符 - 它们不能是public或者private因为它们被限定为函数（即它们只在函数的持续时间内存在，并且不能在函数之外访问）。

下面的示例应该可以正常编译。

// Interface
interface IPhoneBuild
{
    showPhone(): string;
    checkPhone(): boolean;
}

class Phone
{
    Code: string;
    Number: string;
    Fax: boolean;
}

// Module
module Phones
{
    // Class
    export class PhoneBuild implements IPhoneBuild
    {
        private phone: Phone;

        // Constructor
        constructor(phoneNumber: string, code: string, public codes: string[])
        {
            this.phone = this.buildPhone(phoneNumber, code);
        }

        //Private Methods
        private clearPhone(reg: string)
        {
            var re = /\W/g;
            return reg.replace(re, "");
        }

        private buildPhone(num: string, code: string)
        {
            var phone: Phone = { Code: "", Number: "", Fax: false };

            num = this.clearPhone(num);

            if (num.length == 6)
            {
                phone.Code = code;
                phone.Number = num;
            }

            if (num.length == 11)
            {
                phone.Code = num.substring(0, 4);
                phone.Number = num.substring(4);
            }

            return phone;
        }

        // Instance member
        public showPhone()
        {
            return this.phone.Code + this.phone.Number;
        }

        public checkPhone()
        {
            return this.phone.Number.length != 7 || this.phone.Code.length == 0;
        }
    }
}