I need to pull data from a site in json format.
I am successfully pulling this data and adding it to the array. I then need to use the data in this string with a for loop.
But sometimes I get the following error. I haven't been able to figure out the reason for this. I'm sending too many requests. (more than 500 in 5 seconds) The code gives an error when adding the total value as "undefined" to the Array array or not. I couldn't solve it.
At least I tried to keep the code running if the total value contains "undefined" but still failed. I keep getting errors.
I would be very grateful for any help. Sorry for my bad english.
error:
var totalArr = tradeCoinHistoryArray[i].total;
TypeError: Cannot read property 'total' of undefined
code:
request(TRADE_HISTORY_URL + coin, function (error, response, body) {
if (!error && response.statusCode == 200) {
var importedJSON = JSON.parse(body);
tradeCoinHistoryArray = importedJSON.data;
for (var i = tradeCoinHistoryArray.length - TRADE_LAST_TRADE_COUNT; i < tradeCoinHistoryArray.length; i++) {
//error line
total = tradeCoinHistoryArray[i].total;
//error line
if(total == undefined){
//console.log("continue if total is undefined";
return
}
The error is due to tradeCoinHistoryArray[i] object not being defined.
You can add a check:
if (tradeCoinHistoryArray[i] && tradeCoinHistoryArray[i].hasOwnProperty('total')) {
total = tradeCoinHistoryArray[i].total;
}
If your error happening on a line you can't expect to correct an error after executing that line. You need to fix that specific line.
So you may choose to define a static alternate value for that variable, or you should define action in the absence of that value.
This prevents error throw, but undefined will be assigned to total.
total = tradeCoinHistoryArray[i]?.total;
This assigns an alternate value to your total.
total = (tradeCoinHistoryArray[i]?.total) ? tradeCoinHistoryArray[i].total : 0;
If you need to stick es5
total = (tradeCoinHistoryArray[i].total !== undefined) ? tradeCoinHistoryArray[i].total:0
You can use:
if (tradeCoinHistoryArray[i]) {
total = tradeCoinHistoryArray[i].total
}