Question

OK.. I really must be crazy. Why would these not print out 3-5 for “a”? I’ve tried two different methodologies to have the array store 3-5 below, and both of them seem.. obvious. There must be something in the underlying translation that I’m just not seeing.

<script>
    var articlesKey = [];
    for(var i = 3; i < 6; i++) {
        articlesKey.push(i);
        document.write('<br>i:'+i);
    }
    for (a in articlesKey)
        document.write("<br>a:"+a);


    articlesKey = [];
    var count = 0;
    for(var i = 3; i < 6; i++) {
        articlesKey[count] = i;
        document.write('<br>i:'+i);
        count++;
    }
    for (a in articlesKey)
        document.write("<br>a:"+a);
</script>

It prints out:

i:3
i:4
i:5
a:0
a:1
a:2
i:3
i:4
i:5
a:0
a:1
a:2

Answer 1

for( a in articlesKey) iterates a through the KEYS of articlesKey (letting you then get the values as articlesKey[a]). There is nothing wrong here.