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    90
    applegrew at rediffmail dot com
    16 years ago
    For newbies like me.

    Creating new arrays:-
    //Creates a blank array.
    $theVariable = array();

    //Creates an array with elements.
    $theVariable = array("A", "B", "C");

    //Creating Associaive array.
    $theVariable = array(1 => "http//google.com", 2=> "http://yahoo.com");

    //Creating Associaive array with named keys
    $theVariable = array("google" => "http//google.com", "yahoo"=> "http://yahoo.com");

    Note:
    New value can be added to the array as shown below.
    $theVariable[] = "D";
    $theVariable[] = "E";
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    15
    Tyler Bannister
    15 years ago
    To delete an individual array element use the unset function

    For example:

    <?PHP
        $arr     = array( "A", "B", "C" );
        unset(     $arr[1] );
            // now $arr = array( "A", "C" );
    ?>

    Unlink is for deleting files.
    up
    0
    justin at jmfrazier dot com
    4 years ago
    Using null as the key when setting an array value is NOT the same as using empty [].
    <?php
      $null     = null;
          $testArray = [];
          $testArray[$null] = 1;
          $testArray[$null] = 2;
          $testArray[$null] = 3;
          $testArray[$null] = 4;
          var_dump($testArray);
    ?>
    Output:
    array(1) {
      '' =>
      int(4)
    }

    <?php
      $testArray     = [];
          $testArray[null] = 1;
          $testArray[null] = 2;
          $testArray[null] = 3;
          $testArray[null] = 4;
          var_dump($testArray);
    ?>
    Output:
    array(1) {
      '' =>
      int(4)
    }

    <?php
      $testArray     = [];
          $testArray[] = 1;
          $testArray[] = 2;
          $testArray[] = 3;
          $testArray[] = 4;
          var_dump($testArray);
    ?>
    Output:
    array(4) {
      [0] =>
      int(1)
      [1] =>
      int(2)
      [2] =>
      int(3)
      [3] =>
      int(4)
    }
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    -3
    web at houhejie dot cn
    6 years ago
    string2array($str):

    $arr=json_decode('["fileno",["uid","uname"],"topingid",["touid",[1,2,[3,4]],"touname"]]');
    print_r($arr);

    output:
    Array ( [0] => fileno [1] => Array ( [0] => uid [1] => uname ) [2] => topingid [3] => Array ( [0] => touid [1] => Array ( [0] => 1 [1] => 2 [2] => Array ( [0] => 3 [1] => 4 ) ) [2] => touname ) )

    when I hope a function string2array($str), "spam2"  suggest this. and It works well~~~hope this helps us,  and add to the Array function list
    up
    -5
    info at curtinsNOSPAMcreations dot com
    14 years ago
    Another way to create a multidimensional array that looks a lot cleaner is to use json_decode.  (Note that this probably adds a touch of overhead, but it sure does look nicer.)  You can of course add as many levels and as much formatting as you'd like to the string you then decode.  Don't forget that json requires " around values, not '!!  (So, you can't enclose the json string with " and use ' inside the string.)

    As an example:

    <?php
        $myarray    ['blah'] = json_decode('[
            {"label":"foo","name":"baz"},
            {"label":"boop","name":"beep"}
        ]'    ,true);

    print_r($myarray)
    ?>
    returns:

    Array
    (
        [blah] => Array
            (
                [0] => Array
                    (
                        [label] => foo
                        [name] => baz
                    )

                [1] => Array
                    (
                        [label] => boop
                        [name] => beep
                    )
            )
    )
    up
    -4
    macnimble at gmail dot com
    15 years ago
    Converting a linear array (like a mysql record set) into a tree, or multi-dimensional array can be a real bugbear. Capitalizing on references in PHP, we can 'stack' an array in one pass, using one loop, like this:

    <?php
    # array_stack()
    # Original idea from:
    # http://www.ideashower.com/our_solutions/
    #   create-a-parent-child-array-structure-in-one-pass/
    function array_stack (&$a, $p = '@parent', $c = '@children')
    {
          $l = $t = array();
      foreach (    $a AS $key => $val):
        if (!    $val[$p]) $t[$key] =& $l[$key];
        else     $l[$val[$p]][$c][$key] =& $l[$key];
            $l[$key] = (array)$l[$key] + $val;
      endforeach;
      return     $a = array('tree' => $t, 'leaf' => $l);
    }

    # Example:
    $node = array();
    $node[1] = array('@parent' => 0, 'title' => 'I am node 1.');
    #     ^-----------------------v Link @parent value to key.
    $node[2] = array('@parent' => 1, 'title' => 'I am node 2.');
    $node[3] = array('@parent' => 2, 'title' => 'I am node 3.');
    $node[4] = array('@parent' => 1, 'title' => 'I am node 4.');
    $node[5] = array('@parent' => 4, 'title' => 'I am node 5.');

    array_stack($node);

    $node['leaf'][1]['title'] = 'I am node one.';
    $node['leaf'][2]['title'] = 'I am node two.';
    $node['leaf'][3]['title'] = 'I am node three.';
    $node['leaf'][4]['title'] = 'I am node four.';
    $node['leaf'][5]['title'] = 'I am node five.';

    echo     '<pre>',print_r($node['tree'],TRUE),'</pre>';
    ?>

    Note that there's no parameter checking on the array value, but this is only to keep the function size small. One could easily a quick check in there to make sure the $a parameter was in fact an array.

    Hope you find it useful. Huge thanks to Nate Weiner of IdeaShower.com for providing the original function I built on.
    up
    -5
    dragos dot rusu at NOSPAM dot bytex dot ro
    14 years ago
    If an array item is declared with key as NULL, array key will automatically be converted to empty string '', as follows:

    <?php
    $a     = array(
            NULL => 'zero',
            1    => 'one',
            2    => 'two');

    // This will show empty string for key associated with "zero" value
    var_dump(array_keys($a));

    // Array elements are shown
    reset($a);
    while(     key($a) !== NULL )
    {
      echo     key($a) . ": ".current($a) . "<br>";// PHP_EOL
          next($a);
    }

    // Array elements are not shown
    reset($a);
    while(     key($a) != NULL ) // '' == null   => no iteration will be executed
    {
      echo     key($a) . ": ".current($a) . "<br>";// PHP_EOL
          next($a);
    }
    up
    -6
    Anonymous
    15 years ago
    @jorge at andrade dot cl
    This variant is faster:
    <?php
    function array_avg($array,$precision=2){
        if(!    is_array($array))
            return     'ERROR in function array_avg(): this is a not array';

        foreach(    $array as $value)
            if(!    is_numeric($value))
                return     'ERROR in function array_avg(): the array contains one or more non-numeric values';
       
            $cuantos=count($array);
      return     round(array_sum($array)/$cuantos,$precision);
    }
    ?>
    up
    -5
    andyd273 at gmail dot com
    15 years ago
    A small correction to Endel Dreyer's PHP array to javascript array function. I just changed it to show keys correctly:

                function array2js($array,$show_keys)
                {
                    $dimensoes = array();
                    $valores = array();
                  
                    $total = count ($array)-1;
                    $i=0;
                    foreach($array as $key=>$value){
                        if (is_array($value)) {
                            $dimensoes[$i] = array2js($value,$show_keys);
                            if ($show_keys) $dimensoes[$i] = '"'.$key.'":'.$dimensoes[$i];
                        } else {
                            $dimensoes[$i] = '"'.addslashes($value).'"';
                            if ($show_keys) $dimensoes[$i] = '"'.$key.'":'.$dimensoes[$i];
                        }
                        if ($i==0) $dimensoes[$i] = '{'.$dimensoes[$i];
                        if ($i==$total) $dimensoes[$i].= '}';
                        $i++;
                    }
                    return implode(',',$dimensoes);
                }
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    -4
    sunear at gmail dot com
    15 years ago
    Made this function to delete elements in an array;

    <?php

    function array_del_elm($input_array, $del_indexes) {
        if (    is_array($del_indexes)) {
                $indexes = $del_indexes;
        } elseif(    is_string($del_indexes)) {
                $indexes = explode($del_indexes, " ");
        } elseif(    is_numeric($del_indexes)) {
                $indexes[0] = (integer)$del_indexes;
        } else return;
            $del_indexes = null;
       
            $cur_index = 0;
        if (    sort($indexes)) for($i=0; $i<count($input_array); $i++) {
            if (    $i == $indexes[$cur_index]) {
                    $cur_index++;
                if (    $cur_index == count($indexes)) return $output_array;
                continue;
            }
                $output_array[] = $input_array[$i];
        }
        return     $output_array;
    }

    ?>

    but then i saw the methods of doing the same by Tyler Bannister & Paul, could see that theirs were faster, but had floors regarding deleting multiple elements thus support of several ways of giving parameters. I combined the two methods to this to this:

    <?php

    function array_del_elm($target_array, $del_indexes) {
        if (    is_array($del_indexes)) {
                $indexes = $del_indexes;
        } elseif(    is_string($del_indexes)) {
                $indexes = explode($del_indexes, " ");
        } elseif(    is_numeric($del_indexes)) {
                $indexes[0] = (integer)$del_indexes;
        } else return;
        unset(    $del_indexes);
       
        for(    $i=0; $i<count($indexes); $i++) {
            unset(    $target_array[$indexes[$i]]);
        }
        return     $target_array;
    }

    ?>

    Fast, compliant and functional ;)
    up
    -5
    webmaster at infoproducts dot x10hosting dot com
    16 years ago
    New value can also be added to the array as shown below.
    $theVariable["google"] = "http//google.com";
    or
    $theVariable["1"] = "http//google.com";
    up
    -10
    contact at greyphoenix dot biz
    16 years ago
    <?php
    //Creating a multidimensional array

    $theVariable = array("Search Engines" =>
    array (
            0=> "http//google.com",
            1=> "http//yahoo.com",
            2=> "http//msn.com/"),

    "Social Networking Sites" =>
    array (
            0 => "http//www.facebook.com",
            1 => "http//www.myspace.com",
            2 => "http//vkontakte.ru",)
    );

    echo     "The first array value is " . $theVariable['Search Engines'][0];
    ?>

    -- Output--
    The first array value is http://google.com
    up
    -10
    gratcypalma at gmail dot com
    11 years ago
    <?php
    function foo() {
        return array(    'name' => 'palma', 'old' => 23, 'language' => 'PHP');
    }
    /* 1. PHP < 5.4.0 */
    $a = foo();
    var_dump($a['name']);

    /* 2. Works ini PHP >= 5.4.0 */

    var_dump(foo()['name']);

    /*
    When i run second method on PHP 5.3.8 i will be show error message "PHP Fatal error:  Can't use method return value in write context"

    http://www.php.net/manual/en/migration54.new-features.php
    */
    up
    -11
    spereversev at envionsoftware dot com
    12 years ago
    <?php
    function array_mask(array $array, array $keys) {
        return     array_intersect_key( $array, array_fill_keys( $keys, 0 ) );
    }
    ?>

    Might be helpful to take a part of associative array containing given keys, for example, from a $_REQUEST array

    array_mask($_REQUEST, array('name', 'email'));
    up
    -13
    thomasdecaux at ebuildy dot com
    15 years ago
    To browse a simple array:

    <?php

    foreach ($myArray AS $myItem)
    {

    }

    ?>

    To browse an associative array:

    <?php

    foreach ($myArray AS $key=>$value)
    {

    }

    ?>

    http://www.ebuildy.com
    up
    -15
    Jack A
    16 years ago
    Note that arrays are not allowed in class constants and trying to do so will throw a fatal error.
    up
    -27
    John Marc
    14 years ago
    Be careful when adding elements to a numeric array.
    I wanted to store some info about some items from a database and decided to use the record id as a key.

    <?php
    $key    =3000000000;
    $DATA[$key]=true;
    ?>

    This will create an array of 30 million elements and chances are, you will use up all memory with these 2 lines

    <?php
    $key    =3000000000;
    $DATA["$key"]=true;
    ?>

    This on the other hand will force the array to be an associative array and will only create the one element
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