How can I force PHP to use strings for array keys?

Question 1

I've come across an old app that uses an id to name type array, for example...

array(1) {
  [280]=>
  string(3) "abc"
}

Now I need to reorder these, and a var_dump() would make it appear that that isn't going to happen while the keys are integers.

If I add an a to every index, var_dump() will show double quotes around the key, my guess to show it is now a string...

array(1) {
  ["280a"]=>
  string(3) "abc"
}

This would let me easily reorder them, without having to touch more code.

This does not work.

$newArray = array();
foreach($array as $key => $value) {
   $newArray[(string) $key] = $value;
}

A var_dump() still shows them as integer array indexes.

Is there a way to force the keys to be strings, so I can reorder them without ruining the array?

Question 2

EDIT:

I assumed that if they are integers, I can't reorder them without changing the key (which is significant in this example). However, if they were strings, I can reorder them how they like as the index shouldn't be interpreted to have any special meaning. Anyway, see my question update for how I did it (I went down a different route).

Actually they dont have to be in numeric order...

array(208=>'a', 0=> 'b', 99=>'c');

Is perfectly valid if youre assigning them manually. Though i agree the integer keys might be misinterpreted as having a sequential meaning by someone although you would think if they were in a non-numeric order it would be evident they werent. That said i think since you had the leeway to change the code as you updated that is the better approach.

Probably not the most efficient way but easy as pie:

$keys = array_keys($data);

$values = array_values($data);
$stringKeys = array_map('strval', $keys);

$data = array_combine($stringKeys, $values);

//sort your data

Question 3

I just have changed my php-5.3.3 from glibc's iconv to GNU libiconv through the manual recompiling of the php iconv extension. Follow these steps:

download php-5.3.3 source code package
extract it and go into php-5.3.3/ext/iconv subdirectory
execute phpize command (if you have no such command then install php-devel package)

(*) edit configure file (vim configure): add iconv_impl_name="" at 4664 line (exact line number on your system configuration may be different):

...
iconv_impl_name=""
    if test -z "$iconv_impl_name"; then
      { $as_echo "$as_me:${as_lineno-$LINENO}: checking if using GNU libiconv" >&5<
...

./configure --with-iconv=/usr/local|grep iconv:
```
checking if using GNU libiconv... yes
```
make
sudo make install

And now I run php -i|grep "iconv impl" and got:

iconv implementation => libiconv

* This trick forces configure to select the GNU libiconv instead of glibc's iconv. By default it checks for glibc's iconv at first step and does not check for GNU libiconv at all.

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

Not possible.. The only way to accomplish something like what your asking is to use something like memcacheD. Or run what you need to run through your webserver. What's running CLI that you cannot run via a web script with a cronjob?

How can I force PHP to use strings for array keys?

Answers

php,arrays