Issues looping through a list of arrays with null data

Question

This is my first question here, hoping you can help. Currently I am trying to loop through an API list of 100 arrays all of which contain one string of data. My loop filters through for numerical data and prints it to a div id. However when I hit data with "#N/A" instead of digits, it breaks my loop. I have tried nesting an if statement that would check if data is null or not, but as it treats null data as an object, this does not work. I have included commented out code to show the things I have tried:

var xhr = new XMLHttpRequest();

var URL = "https://spreadsheets.google.com/feeds/list/0AhySzEddwIC1dEtpWF9hQUhCWURZNEViUmpUeVgwdGc/1/public/basic?alt=json";

xhr.open("GET", URL, false);
xhr.send();

var statusResponseStringify = JSON.stringify(xhr.responseText, "", 2);
var statusResponseParse = JSON.parse(xhr.responseText);
var Find = statusResponseParse.feed.entry;

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


var FTSEContent = statusResponseParse.feed.entry[i].content.$t;
document.getElementById("FTSEName").innerHTML+=FTSEContent + "<br><br>";

var text = FTSEContent;

var value = text.match(/(\d[\d\.]*)/g);

//var price = value[0];
//var change = value[1];

console.log(value);


/*if (typeof value === "number") {
document.getElementById("Change").innerHTML+=value + "<br>";
}
else if (typeof value === null) {
document.getElementById("Change").innerHTML+="N/A" + "<br>";
}
else if (typeof value === "object") {
document.getElementById("Change").innerHTML+="Smell" + "<br>";
}
else {
document.getElementById("Change").innerHTML+="poo" + "<br>";
};*/


if (typeof value == "undefined") {
document.getElementById("Print").innerHTML+="N/A" + "<br>";
}
else {
document.getElementById("Print").innerHTML+=value[0] + "<br>";
};

};

This is the console I get back when I run this code

Could anyone help me with some code ideas to circumvent the null responses when looping. I would ideally like to print the numbers and print an N/A whenever there is a null or #N/A within the API data.

Thank you all!

Answer 1

Rewrite your check: instead of if (typeof value == "undefined") it should be...

if (value === null) { ... }

... as .match() returns null on non-matching, and not undefined .

As a sidenote, your code can be simplified a bit. First, you don't have to repeat the whole statusResponseParse.feed.entry ... expression in FTSEContent, use Find instead:

var FTSEContent = Find[i].content.$t;

Second, my understanding is that you check for number in that content string. In this case, you can adjust your pattern a bit:

var value = FTSEContent.match(/(\d+(?:\.\d+)?)/);

... so it won't consume such illegal numbers as '3..' and '3.14.15' (in the last case, only 3.14 will be matched), and doesn't have to match globally (you only process the first result anyway).