javascript - 如何将值从输入传输到数组？

Question

我想将三个输入的值:“name”、“counter”和“price”传输到数组“products”，然后将其显示在表中。但是当我使用 buttAdd.addEventListener 处理程序添加它们时，新元素不会显示在表中帮助修复此问题

//Product Creation Class
class Product {
    constructor(name, count, price) {
        this.name = name;
        this.count = count;
        this.price = price;
    }
}
// Сlass where products are recorded
class Shop {
    constructor(products) {
        this.products = [];
    }

    //method for adding a product
    addProduct(newProduct) {
        this.products.push(newProduct);
    }

    show() {
        const rows = document.querySelectorAll("#shop .data");
        for (let i = rows.length - 1; i >= 0; i--) {
            const e = rows.item(i);
            e.parentNode.removeChild(e);
        }
        const table = document.getElementById("shop");
        for (let i = 0; i < this.products.length; i++) {
            //create table
            table.innerHTML += `<tr class="data"><td>${this.products[i].name}</td>
    <td>${this.products[i].price}</td>
    <td>${this.products[i].count}</td></tr>`;
        }
    }
}
const formAdd = document.forms[0];
const inputsAdd = formAdd.elements;
const buttAdd = formAdd.elements[3];
buttAdd.addEventListener('click', (e) => {
    for (let i = 0; i <= 3; i++) {
        shop.addProduct(inputsAdd[i].value);
    }
    shop.show();
}, false);
let shop = new Shop();
shop.addProduct(new Product("product 1", 1, 2000));
shop.show();

  <form id="addForm">
            <label for="name" >Name of product</label>
            <input type="text"  id="name" class="input-product">
            <label for="price">Price of product</label>
            <input type="text"  id="price" class="input-product">
            <label for="count">Count of product</label>
            <input type="text"  id="count" class="input-product">
            <button id="add">Add</button>
        </form>
  <table id="shop">
        <caption>Products that are available in the store</caption>
        <tr>
            <th>Name:</th>
            <th id="filter">Price:</th>
            <th>Count:</th>
        </tr>
    </table>

Answer 1

以下是您的代码中的错误。

1. 内部的 for 循环 buttAdd.addEventListener不正确。条件 <=3将迭代 4 次，而输入字段只有 3 个。

2. shop.addProduct(inputsAdd[i].value);是错误的，因为 addProduct shop的方法|需要上课 Product类对象，因此您需要创建新的 Product class对象并通过 constructor 设置输入值.

正确的做法是:

shop.addProduct(new Product(inputsAdd[0].value,inputsAdd[1].value,inputsAdd[2].value));

这是运行片段

//Product Creation Class
class Product {
    constructor(name, count, price) {
        this.name = name;
        this.count = count;
        this.price = price;
    }
}
// Сlass where products are recorded
class Shop {
    constructor(products) {
        this.products = [];
    }

    //method for adding a product
    addProduct(newProduct) {
        this.products.push(newProduct);
    }

    show() {
        const rows = document.querySelectorAll("#shop .data");
        for (let i = rows.length - 1; i >= 0; i--) {
            const e = rows.item(i);
            e.parentNode.removeChild(e);
        }
        const table = document.getElementById("shop");
        for (let i = 0; i < this.products.length; i++) {
            //create table
            table.innerHTML += `<tr class="data"><td>${this.products[i].name}</td>
    <td>${this.products[i].price}</td>
    <td>${this.products[i].count}</td></tr>`;
        }
    }
}
   

     const formAdd = document.forms[0];
    
        const inputsAdd = formAdd.elements;
      
        const buttAdd = formAdd.elements[3];
    
        //console.log(buttAdd);
      
        buttAdd.addEventListener('click', (e) => {
    e.preventDefault();
    shop.addProduct(new Product(inputsAdd[0].value,parseInt(inputsAdd[1].value),inputsAdd[2].value));
            shop.show();
  
}, false);
        let shop = new Shop();
        shop.addProduct(new Product("product 1", 1, 2000));
        shop.show();
   

  <form id="addForm">
            <label for="name" >Name of product</label>
            <input type="text"  id="name" class="input-product">
            <label for="price">Price of product</label>
            <input type="text"  id="price" class="input-product">
            <label for="count">Count of product</label>
            <input type="text"  id="count" class="input-product">
            <button id="add">Add</button>
        </form>
  <table id="shop">
        <caption>Products that are available in the store</caption>
        <tr>
            <th>Name:</th>
            <th id="filter">Price:</th>
            <th>Count:</th>
        </tr>
    </table>