For loop producing 'undefined' before iteration output

Question

I'm stumped as to why my for loops are displaying "undefined" before any of my actual output occurs. I have all variables declared, and using Inspect Element shows no syntax errors.

<!DOCTYPE HTML>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>Untitled Document</title>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
<script>
    $(function(){ 
    "use strict";
        var html, s, vindex;
        var v = ['alpha::one::uno', 'beta::two::dos', 'gamma::three::tres'];
        for (vindex = 0; vindex < v.length; vindex++) {

            s = v[vindex].split('::');
            html += '<div class="inline ' + s[0] + '">\n';
            html += '<h4>' + s[1] + '</h4>';
            html += '<a href="javascript://" class="link">' + s[2] + '</a></div>';
        }
        $("div").append( html );
    });
</script>
</head>

<body>
<div></div>
</body>
</html>

http://jsfiddle.net/a5b6C/1/

Inspect Element allows you to explore and manipulate the DOM; it has nothing to do with JavaScript syntax errors. You're thinking of the JavaScript console. — greenie2600
– greenie2600, Commented Feb 14, 2014 at 21:09

epascarello · Accepted Answer · 2014-02-14 19:26:07Z

6

The undefined string shows up because html is undefined

var html, s, vindex;

var html; is basically the same thing as var html = undefined;

Set it as an empty string.

var html = "", s, vindex;

answered Feb 14, 2014 at 19:26

epascarello

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1 Comment

justacoder Over a year ago

Excuse me while I smack my forehead.

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