我無法顯示隨機選擇的對象

Question

我無法顯示隨機對象和該隨機對象的屬性。這個項目的目標是要有一個stockItems列表，當我按下一個按鈕時，它會選擇一個確定數量的這些對象，並將它們顯示在HTML標籤中。現在，當我嘗試顯示它時，它將打印出[對象]。目標是讓所選對象的屬性位於不同的行上。

這裏是我一起工作的代碼：

function buildShopItems(count) { 
    var shopItems = [], i, itemIndex; 
    count = stockItems.length < count ? stockItems.length : count; 

    function getUniqueRandomItem() { //from stock 
    var item; 
    while (true) { 
     item = stockItems[Math.floor(Math.random() * stockItems.length)]; 
     if (shopItems.indexOf(item) < 0) return item; 
    } 
    } 

    for (i = 0; i < count; i++) { 
    shopItems.push(getUniqueRandomItem()); 
    } 
    return shopItems; 
    console.log(shopItems); 
} 


var stockItems = [ 
    { item: "sword", type: "weapon", weight: "5 lbs.", cost: "10 gold" }, 
    { item: "hammer", type: "weapon", weight: "8 lbs.", cost: "7 gold" } 
    //... 
]; 


var shopItems = buildShopItems(1); 


console.log(shopItems); 

document.getElementById("item").innerHTML = shopItems.item; 
document.getElementById("type").innerHTML = shopItems.type; 
document.getElementById("weight").innerHTML = shopItems.weight; 
document.getElementById("cost").innerHTML = shopItems.cost; 

Answer 1

的問題是與你的indexOf使用。您可以使用indexOf搜索的對象，因爲在JavaScript中，你可以使用==或===沒有比較對象和使用的indexOf ===。還爲你做了一些語法更新。

'use strict' 

const stockItems = [ 
    { item: "sword", type: "weapon", weight: "5 lbs.", cost: "10 gold" }, 
    { item: "hammer", type: "weapon", weight: "8 lbs.", cost: "7 gold" } 
]; 

function isEquivalent(a, b) { 
    // Create arrays of property names 
    const aProps = Object.getOwnPropertyNames(a); 
    const bProps = Object.getOwnPropertyNames(b); 

    // If number of properties is different, 
    // objects are not equivalent 
    if (aProps.length != bProps.length) { 
     return false; 
    } 

    for (let i = 0; i < aProps.length; i++) { 
     const propName = aProps[i]; 

     // If values of same property are not equal, 
     // objects are not equivalent 
     if (a[propName] !== b[propName]) { 
      return false; 
     } 
    } 

    // If we made it this far, objects 
    // are considered equivalent 
    return true; 
} 

// normal indexof will not work with object because it uses strict equality 
function myIndexOf(array, object) {  
    for (let i = 0; i < array.length; i++) { 
     if (isEquivalent(array[i], object)) return i; 
    } 
    return -1; 
} 

function getUniqueRandomItem(shopItems) { //from stock 
    var item; 
    while (true) { 
    item = stockItems[Math.floor(Math.random() * stockItems.length)]; 
    if (myIndexOf(shopItems, item) < 0) return item; 
    } 
} 

function buildShopItems(count) { 
    count = stockItems.length < count ? stockItems.length : count; 
    const shopItems = []; 

    for (let i = 0; i < count; i++) { 
    const item = getUniqueRandomItem(shopItems); 
    shopItems.push(item); 
    } 

    return shopItems; 
} 

const shopItems = buildShopItems(1); 


console.log(shopItems);