First key of php associative array returns undefined index when parsed from CSV

Question

I am having trouble accessing the first index of an associative array when parsing from a csv.

CSV:

ID,COLOR
1,Red
2,Green 
3,Blue

PHP:

function associative_array_from_csv($csv)
{
    $rows   = array_map('str_getcsv', file($csv));
    $header = array_shift($rows);
    $array  = array();

    foreach($rows as $data) {
        $array[] = array_combine($header, $data);
    }

    return $array;
}

$colors = associative_array_from_csv($csv);

Now $colors returns:

[
    [
        "ID"    => "1",
        "COLOR" => "Red",
    ],
    [
        "ID"    => "2",
        "COLOR" => "Green ",
    ],
    [
        "ID"    => "3",
        "COLOR" => "Blue",
    ],
];

But if I try to access the ID of any color:

$colors[0]["ID"]    // returns undefined index: ID
$colors[0]["COLOR"] // returns "Red"

If I loop over the colors I can access the ID like so:

foreach($colors as $color) 
{ 
    print_r(reset($color)); // Prints the ID 
}

But why I can't access it directly like $colors[0]["ID"]?

Thanks

Try trimming your array keys, there may be some weird characters in there. — aynber
– aynber, Commented Apr 14, 2017 at 15:56

user5875234 · Accepted Answer · 2019-03-26 05:50:19Z

10

I had the same issue. The problem was that Excel adds a hidden character to the first cell in the document, for encoding UTF-8 BOM.

I could see this when running:

var_dump(json_encode($array));

This would return:

string(312) "[{"\ufeffemail":"[email protected]","firstName":"import","lastName":"test"},{"\ufeffemail":"[email protected]","firstName":"import","lastName":"test"}]"

To remove the \ufeff character, I did:

$header = preg_replace('/[\x00-\x1F\x80-\xFF]/', '', $header);

In this case, that would be:

function associative_array_from_csv($csv)
{
    $rows   = array_map('str_getcsv', file($csv));
    $header = array_shift($rows);
    $header = preg_replace('/[\x00-\x1F\x80-\xFF]/', '', $header);
    $array  = array();

    foreach($rows as $data) {
        $array[] = array_combine($header, $data);
    }

    return $array;
}

answered Mar 26, 2019 at 5:50

user5875234

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1 Comment

Felix H. Over a year ago

This works very well. You saved my night. I'm so confused why my first index is undefined. Big thanks to questionnaire and you.

user2012783 · Accepted Answer · 2022-09-03 14:05:05Z

1

This worked for me!

header = preg_replace('/[\x00-\x1F\x80-\xFF]/', '', $header);

answered Sep 3, 2022 at 14:05

user2012783

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2 Comments

jasie Over a year ago

Your answer could be improved with additional supporting information. Please edit to add further details, such as citations or documentation, so that others can confirm that your answer is correct. You can find more information on how to write good answers in the help center.

luciomonter Over a year ago

Missing $ at begging :)

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