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对象相等比较打字稿。 无法将对象属性应用于泛型类型

[英]Object equality comparison typescript. Cannot apply Object properties to generic type

Trying to obtain understand better object comparison in Javascript, along with the property access with typescript, I tried to make for my class an Equal comparer from this starting point.为了更好地理解 Javascript 中的对象比较,以及使用 typescript 的属性访问,我试图从这个起点为我的班级制作一个 Equal 比较器。

TypeScript : Object Equality Comparison (Object Equals Object) TypeScript:对象相等比较(对象等于对象)

I know this can be done with stringify and loadash, but I find it interesting to dig into the object properties to apply logic.我知道这可以通过 stringify 和 loadash 来完成,但我发现深入研究对象属性以应用逻辑很有趣。

This is the code to compare the two objects (from the link above):这是比较两个对象的代码(来自上面的链接):

private equals<T>(x: T, y: T): boolean {
    if (x === y) {
      return true; // if both x and y are null or undefined and exactly the same
    }
    if (!(x instanceof Object) || !(y instanceof Object)) {
      return false; // if they are not strictly equal, they both need to be Objects
    }
    if (x.constructor !== y.constructor) {
      // they must have the exact same prototype chain, the closest we can do is
      // test their constructor.
      return false;
    }
    for (const p in x) {
      if (!x.hasOwnProperty(p)) {
        continue; // other properties were tested using x.constructor === y.constructor
      }
      if (!y.hasOwnProperty(p)) {
        return false; // allows to compare x[ p ] and y[ p ] when set to undefined
      }
      if (x[p] === y[p]) {
        continue; // if they have the same strict value or identity then they are equal
      }
      if (typeof (x[p]) !== 'object') {
        return false; // Numbers, Strings, Functions, Booleans must be strictly equal
      }
      if (!this.equals(x[p], y[p])) {
        return false;
      }
    }
    for (const p in y) {
      if (y.hasOwnProperty(p) && !x.hasOwnProperty(p)) {
        return false;
      }
    }
    return true;
  }

My problem is that I cannot access the Object properties constructor and hasOwnProperty.我的问题是我无法访问 Object 属性构造函数和 hasOwnProperty。 I obtain the error:我得到错误:

Property 'hasOwnProperty' does not exist on type 'Vec3'.ts(2339). “Vec3”.ts(2339) 类型上不存在属性“hasOwnProperty”。

I tried to implement the interface:我尝试实现接口:

interface ObjectPropertiesHandlable {
  constructor: void;
  hasOwnProperty: void;
}

So that in the declaration private equals<T extends ObjectPropertiesHandlable>(x: T, y: T): boolean { I can fix the compilation error.所以在声明private equals<T extends ObjectPropertiesHandlable>(x: T, y: T): boolean {我可以修复编译错误。

But if so, the arguments here won't fit:但如果是这样,这里的论点就不适合了:

    if (!this.equals(x[p], y[p])) {
        return false;
      }

As p is of type const p: Extract<keyof Vec3, string> (by the typescript intellisense onHover)由于 p 是const p: Extract<keyof Vec3, string>类型const p: Extract<keyof Vec3, string> (通过打字稿智能感知 onHover)

If I substitute the generic by my class type (it's a Vec3 class, however not relevant) although it has a constructor, I keep having the errors:如果我用我的类类型替换泛型(它是一个Vec3类,但不相关),尽管它有一个构造函数,我仍然有错误:

Property 'hasOwnProperty' does not exist on type 'Vec3'.ts(2339). “Vec3”.ts(2339) 类型上不存在属性“hasOwnProperty”。

Property 'constructor' does not exist on type 'Vec3'.ts(2339).类型“Vec3”.ts(2339) 上不存在属性“构造函数”。

If I apply an interface to avoid the object property error, I obtain this error:如果我应用一个接口来避免对象属性错误,我会得到这个错误:

在此处输入图片说明

to make it work, try next code :要使其工作,请尝试下一个代码:

type Indexed = {
  [index: string]: unknown
}

const equals = <T extends Indexed>(x: T, y: T) => {
  // ... your code
}

You just should asure TS that your arguments are actually objects.您只需向 TS 保证您的参数实际上是对象。

Please take a look on answer请看一下答案

UPDATE Try:更新尝试:

type Indexed = {
  [index: string]: Indexed
}

I ti a little bit dirty, but if you will explain me what are U trying to achieve maybe I will provide better solution我有点脏,但如果你能向我解释你想要实现的目标,也许我会提供更好的解决方案

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