Question

I am using exif_read_data to store data for an image in an array.

It reads jpeg files from a directory and not every image file has the same exact exif data, some files may have ExposureTime and some may not.

$exif = array();
$exif = exif_read_data('path/to/file');

$file_info = array(
 'FocalLength' => $exif['FocalLength'],
 'ExposureTime' => $exif['ExposureTime'],
 'FNumber' => $exif['FNumber']
);

Not every image may have focallength, exposuretime and fnumber, so it will display undefined index errors.

Is it possible to detect empty index’s and just put ” in place of it, so it’d look like this (if there was no exposuretime and fnumber for that image):

$file_info = array(
 'FocalLength' => $exif['FocalLength'],
 'ExposureTime' => '',
 'FNumber' => ''
);

Answer 1

Simply use the array union operator + to add values to an array if and only if the keys don’t exist yet:

$exif = exif_read_data('path/to/file');
$exif += array(
    'FocalLength'  => null,
    'ExposureTime' => null,
    'FNumber'      => null
);

You should also use null rather than empty strings for “no value” values.