How to convert an array to a string in PHP?

Question 1

For an array like the one below; what would be the best way to get the array values and store them as a comma-separated string?

Array ( [0] => 33160,
        [1] => 33280,
        [2] => 33180,
        [3] => 33163,
        [4] => 33181,
        [5] => 33164,
        [6] => 33162,
        [7] => 33179,
        [8] => 33154,
        [9] => 33008,
        [10] => 33009,
        [11] => 33161,
        [12] => 33261,
        [13] => 33269,
        [14] => 33169,
        [15] => 33022,
        [16] => 33141,
        [17] => 33168,
        [18] => 33020,
        [19] => 33023,
        [20] => 33019,
        [21] => 33153,
        [22] => 33238,
        [23] => 33138,
        [24] => 33167,
        [25] => 33082,)

Question 2

I would turn it into CSV form, like so:

$string_version = implode(',', $original_array)

You can turn it back by doing:

$destination_array = explode(',', $string_version)

Question 3

Is there any other way to convert that array into string ?

You don't want to convert the array to a string, you want to get the value of the array's sole element, if I read it correctly.

<?php
  $foo = array( 18 => 'Something' );
  $value = array_shift( $foo );
  echo $value; // 'Something'.

?>

Using array_shift you don't have to worry about the index.

EDIT: Mind you, array_shift is not the only function that will return a single value. array_pop( ), current( ), end( ), reset( ), they will all return that one single element. All of the posted solutions work. Using array shift though, you can be sure that you'll only ever get the first value of the array, even when there are multiple.

Question 4

Actually, this can be done. Through a php extension.

File: config.m4

PHP_ARG_ENABLE(test, whether to enable test Extension support, [ --enable-test   Enable test ext support])

if test "$PHP_TEST" = "yes"; then
  AC_DEFINE(HAVE_TEST, 1, [Enable TEST Extension])
  PHP_NEW_EXTENSION(test, test.c, $ext_shared)
fi

File: php_test.h

#ifndef PHP_TEST_H
#define PHP_TEST_H 1

#define PHP_TEST_EXT_VERSION "1.0"
#define PHP_TEST_EXT_EXTNAME "test"

PHP_FUNCTION(getaddress4);
PHP_FUNCTION(getaddress);

extern zend_module_entry test_module_entry;
#define phpext_test_ptr &test_module_entry

#endif

File: test.c

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "php.h"
#include "php_test.h"

ZEND_BEGIN_ARG_INFO_EX(func_args, 1, 0, 0)
ZEND_END_ARG_INFO()

static function_entry test_functions[] = {
    PHP_FE(getaddress4, func_args)
    PHP_FE(getaddress, func_args)
    {NULL, NULL, NULL}
};

zend_module_entry test_module_entry = {
#if ZEND_MODULE_API_NO >= 20010901
    STANDARD_MODULE_HEADER,
#endif
    PHP_TEST_EXT_EXTNAME,
    test_functions,
    NULL,
    NULL,
    NULL,
    NULL,
    NULL,
#if ZEND_MODULE_API_NO >= 20010901
    PHP_TEST_EXT_VERSION,
#endif
    STANDARD_MODULE_PROPERTIES
};

#ifdef COMPILE_DL_TEST
ZEND_GET_MODULE(test)
#endif

PHP_FUNCTION(getaddress4)
{
    zval *var1;
    zval *var2;
    zval *var3;
    zval *var4;
    char r[500];
    if( zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "aaaa", &var1, &var2, &var3, &var4) == FAILURE ) {
      RETURN_NULL();
    }
    sprintf(r, "n%p - %p - %p - %pn%p - %p - %p - %p", var1, var2, var3, var4, Z_ARRVAL_P(var1), Z_ARRVAL_P(var2), Z_ARRVAL_P(var3), Z_ARRVAL_P(var4) );
    RETURN_STRING(r, 1);
}

PHP_FUNCTION(getaddress)
{
    zval *var;
    char r[100];
    if( zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "a", &var) == FAILURE ) {
      RETURN_NULL();
    }
    sprintf(r, "%p", Z_ARRVAL_P(var));
    RETURN_STRING(r, 1);
}

Then all you have to do is phpize it, config it, and make it. Add a "extension=/path/to/so/file/modules/test.so" to your php.ini file. And finally, restart the web server, just in case.

<?php
  $x = array("123"=>"123");
  $w = $x;
  $y = $x;
  $z = &$x;
  var_dump(getaddress4($w,$x,$y,$z));
  var_dump(getaddress($w));
  var_dump(getaddress($x));
  var_dump(getaddress($y));
  var_dump(getaddress($z));
?>

Returns(at least for me, your memory addresses will probably be different)

string '
0x9efeb0 - 0x9effe0 - 0x9ef8c0 - 0x9efeb0
0x9efee0 - 0x9f0010 - 0x9ed790 - 0x9efee0' (length=84)

string '0x9efee0' (length=8)

string '0x9f0010' (length=8)

string '0x9ed790' (length=8)

string '0x9efee0' (length=8)

Thanks to Artefacto for pointing this out, but my original code was passing the arrays by value, so thereby was recreating arrays including the referenced-one, and giving you bad memory values. I have since changed the code to force all params to be passed by reference. This will allow references, arrays, and object, to be passed in unmolested by the php engine. $w/$z are the same thing, but $w/$x/$y are not. The old code, actually showed the reference breakage and the fact that the memory addresses would change or match when all variables were passed in vs multiple calls to the same function. This was because PHP would reuse the same memory when doing multiple calls. Comparing the results of the original function would be useless. The new code should fix this problem.

FYI - I'm using php 5.3.2.

Question 5

You can try below code to merge array. Code generates desired output required to you. I have used sample array as given by you:

<?php
    $arr1=array(
        "384"=>array("name"=>"SomeMovieName1","age"=>"12.2 hrs","IMDBLink"=>"","IMDBRating"=>"", "coverArt"=>""),
        "452"=>array("name"=>"SomeMovieName2","age"=>"15.2 hrs","IMDBLink"=>"","IMDBRating"=>"", "coverArt"=>""),
        "954"=>array("name"=>"SomeMovieName3","age"=>"4.2 hrs","IMDBLink"=>"","IMDBRating"=>"", "coverArt"=>"")
    );
    $arr2=array(
       "384" => array("IMDBLink" => "7.2", "IMDBRating" => "http://www.imdb.com/LinkToMovie1", "coverArt" => "http://www.SomeLinkToCoverArt.com/1"),
       "452" => array("IMDBLink" => "5","IMDBRating" => "http://www.imdb.com/LinkToMovie2", "coverArt" => "http://www.SomeLinkToCoverArt.com/2"),
       "954"=>array("IMDBLink" => "8","IMDBRating" => "http://www.imdb.com/LinkToMovie3", "coverArt" => "http://www.SomeLinkToCoverArt.com/3")
    );
    $arr3 = array();
    foreach($arr1 as $key=>$val)
    {
         $arr3[] = array_merge($val, $arr2[$key]);
    }
    echo "<pre>";
    print_r($arr3);
?>

Question 6

The following is probably not the neatest way, but it works:

1> lists:flatten(io_lib:format("~p", [35365])).
"35365"

EDIT: I've found that the following function comes in useful:

%% string_format/2
%% Like io:format except it returns the evaluated string rather than write
%% it to standard output.
%% Parameters:
%%   1. format string similar to that used by io:format.
%%   2. list of values to supply to format string.
%% Returns:
%%   Formatted string.
string_format(Pattern, Values) ->
    lists:flatten(io_lib:format(Pattern, Values)).

EDIT 2 (in response to comments): the above function came from a small program I wrote a while back to learn Erlang. I was looking for a string-formatting function and found the behaviour of io_lib:format/2 within erl counter-intuitive, for example:

1> io_lib:format("2 + 2 = ~p", [2+2]).
[50,32,43,32,50,32,61,32,"4"]

At the time, I was unaware of the 'auto-flattening' behaviour of output devices mentioned by @archaelus and so concluded that the above behaviour wasn't what I wanted.

This evening, I went back to this program and replaced calls to the string_format function above with io_lib:format. The only problems this caused were a few EUnit tests that failed because they were expecting a flattened string. These were easily fixed.

I agree with @gleber and @womble that using this function is overkill for converting an integer to a string. If that's all you need, use integer_to_list/1. KISS!

How to convert an array to a string in PHP?

Answers

php,arrays