JavaScript來計算環路輸出的平均值

Question

我想擺脫「未定義」，並平均輸出到控制檯的priceList數組值。我使用https://experts.shopify.com/designers網頁在Chrome控制檯中應用此代碼。感謝您的幫助！

//selects the all of the designer cards 
var experts = document.querySelectorAll('.expert-card__content'); 

//This tells us how many designer cards there are 
var expertsQty = experts.length; 
var expertContent =document.getElementsByClassName("expert-list-summary txt--minor"); 

//expertContent[0].innerText 
var i; 
var priceMedian; 
var prices; 
var priceList = 0; 

for(i=0; i<experts.length; i++){ 

    //Grabs the content 
    var str = expertContent[i].innerText; 

    //This determines the position of the last $ in the text 
    var strPosition = expertContent[i].innerText.lastIndexOf("$"); 

    //This goes to the position of the $ and shows the 1 word after it. 
    var expertPrice= str.substring(strPosition + 1); 

    //iterate through expert content 
    parseInt(expertPrice); 
    parseInt(prices); 
    priceList = prices += expertPrice; 
    } 

Answer 1

我看了看在你提供的鏈接網站。以下是計算平均值的一種方法：

// get the second <p>s of inside the <div>s with the classes expert-list-summary and txt--minor 
var experts = document.querySelectorAll(".expert-list-summary.txt--minor p:nth-child(2)"); 

var qty = experts.length;       // the quantity is the cound of those p elements 
var prices = 0;         // prices must be initialized to 0 (otherwise you get an average of NaN) 

for(var i = 0; i < experts.length; i++) { 
    var str = experts[i].textContent;    // get the text content of that p element 
    str = str.replace(/,/g, '');     // remove commas as they're not valid in numbers 
    var price = parseInt(str.match(/\$(\d+)/)[1]); // use a rgular expression to retrieve the number it's clearer (match any number after the dollar sign, read more about regular expressions) 
    prices += price;        // add this price to the prices (accumulate the prices) 
} 

var average = prices/qty;      // the average is the sum of prices divided by the quantity