引用错误，对象名称没有定义。

Question

我试图让这个程序与HTML一起在DOM中显示--然而，在JavaScript控制台中，它却给了我这个错误。

Uncaught ReferenceError: phoneBrand is not defined
    at test.js:74
    at Array.filter (<anonymous>)
    at getMatchingPlans (test.js:73)
    at test.js:104

我已经尝试用不同的方式来修改，比如重做对象声明，但是我仍然有这个问题。如果能得到如何解决这个问题的信息，我将非常感激。

const phones = [{
        name: "iPhone XS", brand: "Apple", cost: 43, data: "500MB", minutes: "Unlimited", texts: "Unlimited"
    },
        {
            name: "iPhone 11", brand: "Apple", cost: 64, data: "90GB", minutes: "Unlimited", texts: "Unlimited"
        },
        {
            name: "Galaxy S10", brand: "Samsung", cost: 30, data: "20GB", minutes: "Unlimited", texts: "Unlimited"
        },
        {
            name: "Galaxy S10", brand: "Samsung", cost: 65, data: "Unlimited", minutes: "Unlimited", texts: "Unlimited"
        },
        {
            name: "Galaxy A10", brand: "Samsung", cost: 11.99, data: "500MB", minutes: 250, texts: "Unlimited"
        },
        {
            name: "Galaxy S9", brand: "Samsung", cost: 31, data: "20GB", minutes: "Unlimited", texts: "Unlimited"
        },
        {
            name: "StarTAC 130", brand: "Motorola", cost: 3, data: "0MB", minutes: 200, texts: 500
        },
        {
            name: "Pixel 3A", brand: "Google", cost: 23, data: "4GB", minutes: "Unlimited", texts: "Unlimited"
        },
        {
            name: "Xperia 10", brand: "Sony", cost: 30, data: "20GB", minutes: "Unlimited", texts: "Unlimited"
        },
        {
            name: "P30", brand: "Huawei", cost: 27.99, data: "500MB", minutes: 500, texts: "Unlimited"
        }];






    // Functions

    function getUserPreferences() {

        // These are asking the user for entry of the data into the system.
            const userPrompt = [
            {
                phoneBrand: prompt("Enter a brand name") 
            },

            {
                phoneCost: prompt("Enter a monthly cost") 
            },

            {
                phoneData: prompt("Enter the amount of data") 
            },

            {
                phoneMins: prompt("How many minutes?") 
            },

            {
                phoneTexts: prompt("How many texts?") 
            },



            ]

    }

    function getMatchingPlans() {

        // This is then filtering the object of phones to match what the user has entered into the system.

        const matchingPhones = phones.filter(function(phone) {
            if(phone.brand===phoneBrand && phone.cost.toString()<=phoneCost && phone.data<=phoneData && phone.minutes.toString()<=phoneMins && phone.texts.toString()<=phoneTexts) {
                    return true;
        }
         return false;

    })

    }

    function printResults() {

        // This is then displaying data in the system.

            const returnPhones = document.querySelector("#returnPhones");

            matchingPhones.forEach(function(phone) {

            const newList = document.createElement("ul");
            newList.textContent=phone.name;
            returnPhones.appendChild(newList);

    })


    }




    const userPrefs = getUserPreferences();
    const matchingPlans = getMatchingPlans(userPrefs);
    printResults(matchingPlans);

Answer 1

正如错误信息所说，你使用了 phoneBrand 标识符，它没有被定义--它不是函数参数，不是变量。

你可能需要把它作为 getMatchingPlans 函数，以及那里使用的其他标识符。phoneCost, phoneData、等。

Answer 2

2 错误。

1. 你没有在getUserPreferences函数中返回userPrompt，所以在 "const userPrefs = getUserPreferences(); "之后userPredfs仍然没有定义。
2. 你把userPrompt传给了getMatchingPlans(userPrefs)，但是在getMatchingPlans声明中 "function getMatchingPlans() {"你没有使用这个参数。