How to reproduce the above error in PHP:
php> $yarr = array(3 => 'c', 4 => 'd');
php> echo $yarr[4];
d
php> echo $yarr[1];
PHP Notice: Undefined offset: 1 in
/usr/local/lib/python2.7/dist-packages/phpsh/phpsh.php(578) :
eval()'d code on line 1
What does that error message mean?
It means the php compiler looked for the key 1
and ran the hash against it and didn't find any value associated with it then said Undefined offset: 1
How do I make that error go away?
Ask the array if the key exists before returning its value like this:
php> echo array_key_exists(1, $yarr);
php> echo array_key_exists(4, $yarr);
1
If the array does not contain your key, don't ask for its value. Although this solution makes double-work for your program to "check if it's there" and then "go get it".
Alternative solution that's faster:
If getting a missing key is an exceptional circumstance caused by an error, it's faster to just get the value (as in echo $yarr[1];
), and catch that offset error and handle it like this: https://stackoverflow.com/a/5373824/445131