How do I store an array in a file to access as an array later with PHP?

Solution 1:

The best way to do this is JSON serializing. It is human readable and you'll get better performance (file is smaller and faster to load/save). The code is very easy. Just two functions

• json_encode
• json_decode

Example code:

$arr1 = array ('a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5);
file_put_contents("array.json",json_encode($arr1));
# array.json => {"a":1,"b":2,"c":3,"d":4,"e":5}
$arr2 = json_decode(file_get_contents('array.json'), true);
$arr1 === $arr2 # => true

You can write your own store_array and restore_array functions easily with this example.

For speed comparison see benchmark originally from Preferred method to store PHP arrays (json_encode vs serialize).

Solution 2:

If you don't need the dump file to be human-readable, you can just serialize() the array.

storing:

file_put_contents('yourfile.bin', serialize($array));

retrieving:

$array = unserialize(file_get_contents('yourfile.bin'));

Solution 3:

Use serialize and unserialize

// storing
$file = '/tmp/out.data';
file_put_contents($file, serialize($mydata)); // $mydata is the response from your remote API

// retreiving
$var = unserialize(file_get_contents($file));

Or another, hacky way:

var_export() does exactly what you want, it will take any kind of variable, and store it in a representation that the PHP parser can read back. You can combine it with file_put_contents to store it on disk, and use file_get_contents and eval to read it back.

// storing
$file = '/tmp/out.php';
file_put_contents($file, var_export($var, true));

// retrieving
eval('$myvar = ' . file_get_contents($file) . ';');

Solution 4:

Another fast way not mentioned here:

That way add header with <?php start tag, name of variable \$my_array = with escaped \$ and footer ?> end tag.

Now can use include() like any other valid php script.

<?php
  // storing
  $file = '/tmp/out.php';
  $var = ['a'=>1,'b'=>2,'c'=>3,'d'=>4,'e'=>5];

  file_put_contents($file,
    "<?php\n\$my_array = "
      .var_export($var, true)
    .";\n?>"
  );

  // retrieving as included script
  include($file);

  //testing
  print_r($my_array);
?>

out.php will look like this

<?php
  $my_array = array (
    'a'=>1,
    'b'=>2,
    'c'=>3,
    'd'=>4,
    'e'=>5
  );
?>