javascript - 我找不到错误 TypeError: Cannot read properties of undefined (reading 'name')

问题描述

我是反应新手，当我试图从我的反应应用程序的一个名为“products.js”的文件中的一组对象中带来一些“产品”时，我需要一些帮助。

问题是我能够在主屏幕的数组中绘制产品。但是，当我尝试在我的详细信息产品页面上绘制这些产品时（这个页面是我可以看到单个产品详细信息的页面）“ProductDetails.js”我收到错误（无论我是否尝试使用 product.name 或product.price 或其他）：

TypeError：无法读取未定义的属性（读取“名称”）

为了让您了解我在说什么，我将与您分享我的代码中的一些片段，以便您了解上下文。我将从确切的错误消息开始，我将以概览我的项目依赖项结束。

错误信息

TypeError: Cannot read properties of undefined (reading 'name')
ProductDetails
C:/Users/jjimennz/OneDrive/Desktop/eCommerce MERN Stack/Sprint1/frontend/src/views/ProductDetails.js:19

 16 | const ProductDetails = ({ match }) => {
  17 |   const product = products.find((p) => p._id === match.params.id);
  18 | 
> 19 |   return <div>{product.name}</div>;
  20 | };
  21 | 
  22 | export default ProductDetails;

这是我遇到麻烦的视图，不仅是“product.name”，我还遇到了任何“product.price”“product.image”......这是详细的产品屏幕，应该是视图在自己的页面上向我展示每个单独的产品及其详细信息，我称之为“ProductDetails.js”

import React from "react";
import products from "../products";

const ProductDetails = ({ match }) => {
  const product = products.find((p) => p._id === match.params.id);

  return <div>{product.name}</div>;
};

export default ProductDetails;

这是包含我要在上述产品详细信息屏幕上绘制的产品的数组的文件。这个文件是一个名为“products.js”的文件：

const products = [
  {
    _id: 1,
    name: "Nemeziz 19.4",
    image:
      "https://assets.adidas.com/images/w_600,f_auto,q_auto/75987ad2e31644d59d24ab3000fce766_9366/Botines_Nemeziz_19.4_Pasto_Sintetico_Verde_FV3317_41_detail.jpg",
    description: "Breve descripcion de los zapatos",
    brand: "Adidas",
    category: "Zapatos",
    price: 89.99,
    countInStock: 20,
    rating: 4.5,
    numReviews: 14,
  },
  {
    _id: 2,
    name: "Adidas Ace",
    image: "https://www.sports-ws.com/img/item/F163AD0/F163AD0654.jpg",
    description: "Breve descripcion de los zapatos",
    brand: "Adidas",
    category: "Zapatos",
    price: 149.99,
    countInStock: 8,
    rating: 4.5,
    numReviews: 15,
  },
];

export default products

这是主屏幕的视图，我在其中显示了上述数组中的所有产品，这个效果很好，并且在屏幕上绘制了数组中的每个产品。这个叫做“HomeScreen.js”

import React from "react";
import { Row, Col } from "react-bootstrap";
import Product from "../components/Product";
import products from "../products";

const HomeScreen = () => {
  return (
    <>
      <h1>Latest Products</h1>
      <Row>
        {products.map((product) => (
          <Col key={product._id} sm={12} md={6} lg={4} xl={3}>
            <Product product={product} />
          </Col>
        ))}
      </Row>
    </>
  );
};

export default HomeScreen;

这是 Product 组件，它基本上在上面的主屏幕视图的数组中绘制每个单独的产品。这个作为上面的主屏幕也很好用，它给我带来了带有名称、价格和图像的产品。我确实称这个组件为“Product.js” *

import React from "react";
import { Link } from "react-router-dom";
import { Card } from "react-bootstrap";
import Rating from "./Rating";

const Product = ({ product }) => {
  return (
    <Card className="my-3 p-3 rounded">
      <Link to={`/product/${product._id}`}>
        <Card.Img src={product.image} variant="top" />
      </Link>
      <Card.Body>
        <Link to={`/product/${product._id}`}>
          <Card.Title as="div">
            <strong>{product.name}</strong>
          </Card.Title>
        </Link>

        <Card.Text as="div">
          <Rating
            value={product.rating}
            text={`${product.numReviews} reviews`}
          />
        </Card.Text>
        <Card.Text as="h3">${product.price}</Card.Text>
      </Card.Body>
    </Card>
  );
};

export default Product;

“App.js”文件，这样您就可以更好地了解我的项目正在发生的事情

import React from "react";
import { BrowserRouter as Router, Route } from "react-router-dom";
import { Container } from "react-bootstrap";
import Header from "./components/Header";
import Footer from "./components/Footer";
import HomeScreen from "./views/HomeScreen";
import ProductDetails from "./views/ProductDetails";

function App() {
  return (
    <Router>
      <Header />
      <main className="py-3">
        <Container>
          <Route path="/" component={HomeScreen} exact />
          <Route path="/product/:id" component={ProductDetails} />
        </Container>
      </main>
      <Footer />
    </Router>
  );
}

export default App;

这是我的项目中包含依赖项的“package.json”文件，以防万一它有助于帮助我

{
  "name": "frontend",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "@testing-library/jest-dom": "^5.14.1",
    "@testing-library/react": "^11.2.7",
    "@testing-library/user-event": "^12.8.3",
    "react": "^17.0.2",
    "react-bootstrap": "^2.0.0",
    "react-dom": "^17.0.2",
    "react-router-bootstrap": "^0.25.0",
    "react-router-dom": "^5.3.0",
    "react-scripts": "4.0.3",
    "web-vitals": "^1.1.2"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test",
    "eject": "react-scripts eject"
  },
  "eslintConfig": {
    "extends": [
      "react-app",
      "react-app/jest"
    ]
  },
  "browserslist": {
    "production": [
      ">0.2%",
      "not dead",
      "not op_mini all"
    ],
    "development": [
      "last 1 chrome version",
      "last 1 firefox version",
      "last 1 safari version"
    ]
  }
}

在这里，您有产品详细信息视图上的错误消息的屏幕截图

在这里，您有一个适用于主屏幕的页面的屏幕截图

标签： javascriptreactjsreact-hooksreact-routerreact-bootstrap

javascript - 我找不到错误 TypeError: Cannot read properties of undefined (reading 'name')

问题描述

解决方案

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