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

Question

I just want to quickly store an array which I get from a remote API, so that i can mess around with it on a local host.

So:

1. I currently have an array.<

Answer 1

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) . ';');

Answer 2

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).

Answer 3

You can use serialize to make it into a string to write to file, and the accompanying unserialize to return it to an array structure.

I'd suggest using a language independent structure though, such as JSON. This will allow you to load the files using different languages than PHP, in case there's a chance of that later. json_encode to store it and json_decode($str, true) to return it.

Answer 4

Use php's serialze:

file_put_contents("myFile",serialize($myArray));

Answer 5

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.

// storing
$file = '/tmp/out.php';
file_put_contents($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
  );
?>

Answer 6

I made a tiny library (~2 KB; <100 lines) that allows you to do just this: varDx

It has functions to write, read, modify, check and delete data. It implements serialization, and therefore supports all data types.

Here's how you can use it:

<?php
require 'varDx.php';
$dx = new \varDx\cDX; //create an object
$dx->def('file.dat'); //define data file

$val1 = "this is a string";
$dx->write('data1', $val1); //writes key to file
echo $dx->read('data1'); //returns key value from file

In your specific case:

$array1 = array(
    "foo" => "bar",
    "bar" => "foo",
);

//writing the array to file
$dx->write('myarray', $array1);

//reading array from file
$array2 = $dx->read('myarray')

//modifying array in file after making changes
$dx->write('myarray', $array2);