在打字稿中打印对象时打印吸气剂

Question

TypeScript/JavaScript 中是否有一个选项可以使用 getter 打印具有私有属性的对象，而不是打印私有属性名称。

例如我在 TypeScript 中有这个 class

class Vehicle {

  constructor(private _brand: string, private _year: number) {}

  get brand(): string {
    return this._brand;
  }

  get year(): number {
    return this._year;
  }

  set year(year: number) {
    this._year = year;
  }

  set brand(brand: string) {
    this._brand = brand;
  }
}

const vehicle: Vehicle = new Vehicle('Toyota', 10);

console.log(vehicle);

我知道了

[LOG]: Vehicle: {
  "_brand": "Toyota",
  "_year": 10
}

但我想知道我是否能得到这样的东西

[LOG]: Vehicle: {
  "brand": "Toyota",
  "year": 10
}

Answer 1

我认为没有办法做到这一点，但您可以在 class 中创建一个日志方法，如下所示：

  log() {
    console.log({
      brand: this.brand,
      year: this.year,
    });
  }

然后只需调用 vehicle.log();

然后你会得到这样的日志{brand: 'Toyota', year: 10}

Answer 2

console.log 的作用因环境而异。如果你想做你正在描述的事情，你必须编写自己的记录器函数，例如（在 JavaScript 中，但类型很容易添加）见评论：

function log(obj) {
    // Get the names of getter properties defined on the prototype
    const ctor = obj.constructor;
    const proto = ctor?.prototype;
    const names = new Set(
        proto
            ? Object.entries(Object.getOwnPropertyDescriptors(proto))
                .filter(([_, {get}]) => !!get)
                .map(([name]) => name)
            : []
    );
    // Add in the names of "own" properties that don't start with "_"
    for (const name of Object.keys(obj)) {
        if (!name.startsWith("_")) {
            names.add(name);
        }
    }
    // Create a simple object with the values of those properties
    const simple = {};
    for (const name of names) {
        simple[name] = obj[name];
    }
    // See if we can get a "constructor" name for it, apply it if so
    let objName =
        obj[Symbol.toStringTag]
        || ctor?.name;
    if (objName) {
        simple[Symbol.toStringTag] = objName;
    }
    // Log it
    console.log(simple);
}

实例：

"use strict";

function log(obj) {
    // Get the names of getter properties defined on the prototype
    const ctor = obj.constructor;
    const proto = ctor?.prototype;
    const names = new Set(
        proto
            ? Object.entries(Object.getOwnPropertyDescriptors(proto))
                .filter(([_, {get}]) => !!get)
                .map(([name]) => name)
            : []
    );
    // Add in the names of "own" properties that don't start with "_"
    for (const name of Object.keys(obj)) {
        if (!name.startsWith("_")) {
            names.add(name);
        }
    }
    // Create a simple object with the values of those properties
    const simple = {};
    for (const name of names) {
        simple[name] = obj[name];
    }
    // See if we can get a "constructor" name for it, apply it if so
    let objName =
        obj[Symbol.toStringTag]
        || ctor?.name;
    if (objName) {
        simple[Symbol.toStringTag] = objName;
    }
    // Log it
    console.log(simple);
}

class Vehicle {
    constructor(_brand, _year) {
        this._brand = _brand;
        this._year = _year;
    }
    get brand() {
        return this._brand;
    }
    get year() {
        return this._year;
    }
    set year(year) {
        this._year = year;
    }
    set brand(brand) {
        this._brand = brand;
    }
}
const vehicle = new Vehicle('Toyota', 10);
log(vehicle);

有很大的空间可以根据自己的喜好进行调整，这只是您可能如何进行的草图。

在打字稿中打印对象时打印吸气剂

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