CODEWITHSUNDEEP
javascriptjqueryjson
Mauritius
Mauritius

Reputation: 105

Jquery json : Uncaught TypeError: Cannot read property 'xx' of undefined

I am retrieving data via JSON but the problem is that I am getting error as such "Cannot read property 'productid' of undefined".

JSON File (data.json)

{
    "Products": [
        {
            "productid": "135",
            "productname": "Shirt",
            "productqty": "3",
            "seller_3": "150.00",
            "seller_2": "151.00",
            "seller_7": "153.00",
            "seller_6": "159.00",
            "seller_5": "155.00",
            "seller_1": "157.00",
            "seller_4": "152.00"
        }
    ]
}

The execution code is 

var itemQty = 134;
$.getJSON( "../data.json", function(data) {
    if (data.Products.length == 0) {
        /*do nothing*/
    } else if(data.Products.length > 0){
        for (var i = 0; i < data.Products.length; i++) {
            console.log(data.Products[i].productid); // ITS RETURN THE VALUE 135
            if (data.Products[i].productid == itemID) { // <--- ERROR THIS LINE
                if (data.Products[i].productqty == itemQty) {
                    newQuantity = eval(data.Products[i].productqty);
                } else {
                    var newQuantity = eval(itemQty);
                }
                if (newQuantity > options.quantityLimit) {
                    newQuantity = options.quantityLimit
                }
                data.Products[i].productqty = newQuantity;
            } else {
                data.Products.push(cartItem);
            }
        }
    }
}

In the console.log, it returns the value which is 135, where as when comparing in the IF statement, I am getting the error Cannot read property 'productid' of undefined.

Upvotes: 1

Views: 3359

Answers (1)

Ryan953
Ryan953

Reputation: 688

It looks like you are modifying the list of Products from inside the loop. So take a closer look at whatever is setting the value for cartItem.

  for (var i = 0; i < data.Products.length; i++) {
    ...
    data.Products.push(cartItem);
  }

It is a bad idea to add new items to a list while you're iterating over it. You are likely to have an infinite loop depending on how itemID and cartItem are set. Try reading the .length value one time before starting the loop, so new items won't be iterated:

for (var i = 0, len = data.Products.length; i < len; i++) {
  ...
}

Upvotes: 2

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