Javascript String Array Access Returns Chars

Question

Okay, so I have an array of strings on a webpage in Javascript, defined like so:

var arr = ["Apple", "Orange", "Pear"]; //this is populated by a php script prior to being sent to the client.

The problem is, when I attempt to access these items in a for loop like this:

for (var i = 0; i < arr.length; i++)
{
    alert(arr[i]);
}

My output would be:

A
p
p

So, the array seems to be accessed one character at a time, which is of course not the reason I created the array.

I really cannot fathom why this would happen. Can anyone see a problem?

EDIT: The full code - it's not very nice but it's a work in progress:

var votes = {<?php foreach ($options as $o) { echo ' "'.$o['name'].'":"'.$o['votes'].'"'; if (next($options)) { echo ','; } } ?>};
var name = [<?php for ($i = 0; $i < count($options); $i++) { echo ' "'.$options[$i]['name'].'"'; if ($i < count($options)-1) { echo ','; } } ?> ];

function run(num) {
document.getElementById('out').innerHTML = '';


for (var i = 0; i < num; i++) {
    if (document.getElementById(i+1).checked)
    {
        votes[name[i]] = (parseInt(votes[name[i]]) + 1);
        document.getElementById(num+(i+1)).checked = true;
    }
    if (document.getElementById(num+(i+1)).checked)
    {
        votes[name[i]] = (parseInt(votes[name[i]]) + 1);
    }

    document.getElementById('out').innerHTML += name[i] + ': ' + votes[name[i]] + '<br />';
    console.log('arr: ', name, 'j: ', name.length);
}

$.ajax("vote.php", {
        data:votes,
            });
}

Here is Options

"options" : [
    {
        "name"  : "Children of Men",
        "id"    : "1",
        "votes" : "0"
    },
    {
        "name"  : "City of God",
        "id"    : "2",
        "votes" : "0"
    },
    {
        "name"  : "Hidden",
        "id"    : "3",
        "votes" : "0"
    },
    {
        "name"  : "We Need To Talk About Kevin",
        "id"    : "4",
        "votes" : "0"
    }
]

That code won't do what you say it's doing, so something must be wrong with the way you're getting the array from your server to the browser. — Pointy
– Pointy, Commented Jan 28, 2013 at 17:26
It sounds like you reassigned arr to be one element of the original arr array. — Ted Hopp
– Ted Hopp, Commented Jan 28, 2013 at 17:26
@Luke: And what is alert(typeof arr)? Sounds like it was a string somehow — Bergi
– Bergi, Commented Jan 28, 2013 at 17:40
@Luke: Not with the above code. Could you please show us your actual code in whole (thanks for the PHP part), what ends up in the source of the page? — Bergi
– Bergi, Commented Jan 28, 2013 at 17:46

Wojciech Bednarski · Accepted Answer · 2013-01-28 18:00:05Z

1

var arr = ['Apple', 'Orange', 'Pear'],
    i,
    j = arr.length;

console.log('Array?: ', arr.toString() == '[object Array]'); // edited

for (i = 0; i < j; i++) {
    console.log('arr: ', arr, 'j: ', j);
}

Above console.log should show you what is wrong.

edited Jan 28, 2013 at 18:00

answered Jan 28, 2013 at 17:35

Wojciech Bednarski

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4 Comments

Luke Over a year ago

in my console.log arr is the contents of the array separated by commas, and j is 62... Which is the number of characters in the 'arr' output. Really cannot figure out why it is doing that.

Wojciech Bednarski Over a year ago

@Luke OK, what about toString.call(arr) == '[object Array]'; is it true?

Wojciech Bednarski Over a year ago

@Luke OK, so you have a string not an array. The problem is in your php code which makes not an array but a string.

Wojciech Bednarski Over a year ago

@Luke Somehow you have structure like this: 'Apple,Orange,Pear' but you need it to be like this: ['Apple','Orange','Pear']

Luke · Accepted Answer · 2013-04-10 12:27:52Z

0

In the end I "fixed" this problem by defining the Array with

new Array( 'Apple', 'Orange', 'Pear' );

I could not figure out the actual issue, unfortunately.

answered Apr 10, 2013 at 12:27

Luke

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