How to solve PHP error 'Notice: Array to string conversion in…'

Question

I have a PHP file that tries to echo a $_POST and I get an error, here is the code:

echo \"\";
echo \"\";
for($i=0; $i&l         


        

Answer 1

What the PHP Notice means and how to reproduce it:

If you send a PHP array into a function that expects a string like: echo or print, then the PHP interpreter will convert your array to the literal string Array, throw this Notice and keep going. For example:

php> print(array(1,2,3))

PHP Notice:  Array to string conversion in 
/usr/local/lib/python2.7/dist-packages/phpsh/phpsh.php(591) :
eval()'d code on line 1
Array

In this case, the function print dumps the literal string: Array to stdout and then logs the Notice to stderr and keeps going.

Another example in a PHP script:

Correction 1: use foreach loop to access array elements

http://php.net/foreach

$stuff = array(1,2,3);
foreach ($stuff as $value) {
    echo $value, "\n";
}

Prints:

1
2
3

Or along with array keys

$stuff = array('name' => 'Joe', 'email' => 'joe@example.com');
foreach ($stuff as $key => $value) {
    echo "$key: $value\n";
}

Prints:

name: Joe
email: joe@example.com

Note that array elements could be arrays as well. In this case either use foreach again or access this inner array elements using array syntax, e.g. $row['name']

Correction 2: Joining all the cells in the array together:

In case it's just a plain 1-demensional array, you can simply join all the cells into a string using a delimiter:

Correction 3: Stringify an array with complex structure:

In case your array has a complex structure but you need to convert it to a string anyway, then use http://php.net/json_encode

$stuff = array('name' => 'Joe', 'email' => 'joe@example.com');
print json_encode($stuff);

Prints

{"name":"Joe","email":"joe@example.com"}

A quick peek into array structure: use the builtin php functions

If you want just to inspect the array contents for the debugging purpose, use one of the following functions. Keep in mind that var_dump is most informative of them and thus usually being preferred for the purpose

• http://php.net/print_r
• http://php.net/var_dump
• http://php.net/var_export

examples

$stuff = array(1,2,3);
print_r($stuff);
$stuff = array(3,4,5);
var_dump($stuff);

Prints:

Array
(
    [0] => 1
    [1] => 2
    [2] => 3
)
array(3) {
  [0]=>
  int(3)
  [1]=>
  int(4)
  [2]=>
  int(5)
}