与变量和类型有关的扩展
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PHP手册

数组

与变量和类型有关的扩展
在线手册：中文 英文
PHP手册
PHP手册 - N: 数组

用户评论:

fo dot q dot who at gmail dot com (06-Apr-2011 12:37)

Just another way to pass a multidimensional php array to a js array, but i think a cool one so I decided to put this on here.

<?php

function array_print($item, $key, $array_name)
{
    if(is_array($item)){
        $array_name = $array_name."['".$key."']";
        echo $array_name ."= Array();". "";
        php_array_to_js_array($item, $array_name);
    }else{
        echo $array_name."['".$key."'] = \"".$item."\";";
    }
}

function php_array_to_js_array($array, $array_name){
    array_walk($array, 'array_print', $array_name);
}

?>
<script type="text/javascript" defer="defer">
<?php
        echo "js_array = Array();";
        php_array_to_js_array($array, "js_array");
       
?>
</script>

there is not much to say about that, its simple and understandable, i think... if not just email me. Have a nice day pplz !!

Patrick F.

info at curtinsNOSPAMcreations dot com (05-Nov-2010 03:49)

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
                )
        )
)

dragos dot rusu at NOSPAM dot bytex dot ro (07-Mar-2010 02:15)

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);
}

John Marc (15-Feb-2010 09:30)

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

sunear at gmail dot com (04-Aug-2009 06:45)

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 ;)

Tyler Bannister (11-Jun-2009 02:59)

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.

thomasdecaux at ebuildy dot com (15-May-2009 09:14)

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

macnimble at gmail dot com (27-Mar-2009 02:59)

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.

andyd273 at gmail dot com (24-Feb-2009 09:12)

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);
            }

Endel Dreyer (20-Jan-2009 12:16)

Function to convert PHP arrays to JavaScript Array Object:
Useful in some cases.

<?php
function array2js($array,$show_keys=false)
{
    $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);
        } else {
            $dimensoes[$i] = '"'.addslashes($value).'"';
            if ($show_keys) '"'.$key.'":'.$dimensoes[$i];
        }
        if ($i==0) $dimensoes[$i] = '['.$dimensoes[$i];
        if ($i==$total) $dimensoes[$i].= ']';
        $i++;
    }
    return implode(',',$dimensoes);
}
?>

Anonymous (26-Nov-2008 06:36)

@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);
}
?>

jorge at andrade dot cl (12-Nov-2008 08:03)

To calculate the average of a array

<?php
function array_avg($array,$precision="2"){
    $a=0;
    if(is_array($array)){
        foreach($array as $value):
            if(!is_numeric($value)){
                $a++;
            }
        endforeach;
        if($a==0){
            $cuantos=count($array);
            return round(array_sum($array)/$cuantos,$precision);
        }else{
            return "ERROR in function array_avg(): the array contains one or more non-numeric values";
        }       
    }else{
        return "ERROR in function array_avg(): this is a not array";
    }
}
?>

alan dot lake at lakeinfoworks dot com (22-Oct-2008 04:46)

To delete an array key (and its value) from an array:

<?php
    function array_delete(&$ary,$key_to_be_deleted)
    {
        $new = array();
        if(is_string($key_to_be_deleted)) {
            if(!array_key_exists($key_to_be_deleted,$ary)) {
                return;
            }
            foreach($ary as $key => $value) {
                if($key != $key_to_be_deleted) {
                    $new[$key] = $value;
                }
            }
            $ary = $new;
        }
        if(is_array($key_to_be_deleted)) {
            foreach($key_to_be_deleted as $del) {
                array_delete(&$ary,$del);
            }
        }
    }
?>

webmaster at infoproducts dot x10hosting dot com (11-Oct-2008 03:13)

New value can also be added to the array as shown below.
$theVariable["google"] = "http//google.com";
or
$theVariable["1"] = "http//google.com";

Jack A (07-Oct-2008 04:14)

Note that arrays are not allowed in class constants and trying to do so will throw a fatal error.

contact at greyphoenix dot biz (01-Jul-2008 05:36)

<?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

applegrew at rediffmail dot com (28-May-2008 04:23)

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";