20

この配列での「写真」の出現をカウントする方法を知っている人はいますか？

    Array ( 
    [0] => stdClass Object ( [type] => photo [id] => 1404781893036 [created_time] => 2012-03-02T07:58:23+0000 ) 
    [1] => stdClass Object ( [type] => photo [id] => 14047818930362 [created_time] => 2012-03-01T14:58:53+0000 ) 
    [2] => stdClass Object ( [type] => status [id] => 1404781893036 [created_time] => 2012-03-01T09:49:40+0000 ) 
    [3] => stdClass Object ( [type] => status [id] => 14047818930362 [created_time] => 2012-03-01T09:36:04+0000 ) 
    [4] => stdClass Object ( [type] => photo [id] => 14047818930362 [created_time] => 2012-02-28T07:03:25+0000 ) 
    [5] => stdClass Object ( [type] => photo [id] => 1404781893036 [created_time] => 2012-02-27T09:15:34+0000 ) 
    [6] => stdClass Object ( [type] => photo [id] => 14047818930362 [created_time] => 2012-02-27T07:32:13+0000 ) 
    [7] => stdClass Object ( [type] => status [id] => 1404781893036 [created_time] => 2012-02-25T09:36:57+0000 )
    [8] => stdClass Object ( [type] => photo [id] => 1404781893036 [created_time] => 2012-02-23T08:46:43+0000 ) 
    [9] => stdClass Object ( [type] => status [id] => 1404781893036 [created_time] => 2012-02-22T21:04:30+0000 ) 
    [10] => stdClass Object ( [type] => status [id] => 1404781893036 [created_time] => 2012-02-21T20:38:27+0000 )
    [11] => stdClass Object ( [type] => photo [id] => 1404781893036 [created_time] => 2012-02-21T07:22:44+0000 ) 
    [12] => stdClass Object ( [type] => status [id] => 14047818930362 [created_time] => 2012-02-20T08:32:46+0000 ) 
    [13] => stdClass Object ( [type] => status [id] => 1404781893036 [created_time] => 2012-02-17T15:00:11+0000 ) )
4

4 に答える 4

57

多次元配列内の文字列の一致する発生をカウントするには、各配列要素を反復処理し、文字列を一致させてカウントをインクリメントする必要があります。同様に@Dorは提案しました

$count = 0;
foreach ($array as $item) {
  if ($item->type === 'photo') {
    $count++;
  }
}

一次元配列で同じことを達成したい場合、それはかなり簡単です。以下で説明するように、array_count_valuesPHP配列関数を使用できます。

<?php
   $array = array(1, "test", 1, "php", "test");
   print_r(array_count_values($array));
?>

上記の例では、次のように出力されます。

Array
(
    [1] => 2
    [test] => 2
    [php] => 1
)
于 2012-11-20T09:55:01.343 に答える
15 
$count = 0;
foreach ($array as $item) {
  if ($item->type === 'photo') {
    $count++;
  }
}
于 2012-03-07T10:08:48.110 に答える
2

Dor Shemerによる方法は、（IMO）最も直接的で、クリーンで、読みやすく、信頼性の高い方法であることを認めたいと思います。関数型プログラミングを使用することを好む人のために、いくつかの選択肢を提供したいと思います...array_reduce()私にとっては2番目に近いです。最後に、使用するメソッドの小さな落とし穴を特定したいと思いますarray_count_values()-読んでください...

メソッドのバッテリー:(デモ）

$photo_count=0;  // establish default value
foreach($array as $objects){
    if($objects->type==='photo') ++$photo_count;  // pre-increment
}
echo "foreach result = $photo_count";

echo "array_reduce = ",array_reduce($array,function($carry,$objects){return $carry+($objects->type==='photo'?1:0);},0);

echo "array_filter & count = ",sizeof(array_filter($array,function($objects){return $objects->type==='photo';}));

echo "array_column & array_filter & count = ",sizeof(array_filter(array_column($array,'type'),function($v){return $v==='photo';}));

echo "array_map & array_count_values & array_replace = ",array_replace(['photo'=>0],array_count_values(array_map(function($o) {return $o->type;}, $array)))['photo'];

echo "array_map & array_count_values (gives Notice) = ",array_count_values(array_map(function($o) {return $o->type;}, $array))['photo'];

OPのサンプルデータを使用した入出力（問題なし）：

$array=[
    (object)['type'=>'photo','id'=>1404781893036,'created_time'=>'2012-03-02T07:58:23+0000'],
    (object)['type'=>'photo','id'=>14047818930362,'created_time'=>'2012-03-01T14:58:53+0000'],
    (object)['type'=>'status','id'=>1404781893036,'created_time'=>'2012-03-01T09:49:40+0000'],
    (object)['type'=>'status','id'=>14047818930362,'created_time'=>'2012-03-01T09:36:04+0000'],
    (object)['type'=>'photo','id'=>14047818930362,'created_time'=>'2012-02-28T07:03:25+0000'],
    (object)['type'=>'photo','id'=>1404781893036,'created_time'=>'2012-02-27T09:15:34+0000'],
    (object)['type'=>'photo','id'=>14047818930362,'created_time'=>'2012-02-27T07:32:13+0000'],
    (object)['type'=>'status','id'=>1404781893036,'created_time'=>'2012-02-25T09:36:57+0000'],
    (object)['type'=>'photo','id'=>1404781893036,'created_time'=>'2012-02-23T08:46:43+0000'],
    (object)['type'=>'status','id'=>1404781893036,'created_time'=>'2012-02-22T21:04:30+0000'],
    (object)['type'=>'status','id'=>1404781893036,'created_time'=>'2012-02-21T20:38:27+0000'],
    (object)['type'=>'photo','id'=>1404781893036,'created_time'=>'2012-02-21T07:22:44+0000'],
    (object)['type'=>'status','id'=>14047818930362,'created_time'=>'2012-02-20T08:32:46+0000'],
    (object)['type'=>'status','id'=>1404781893036,'created_time'=>'2012-02-17T15:00:11+0000']
];

// output:
foreach result = 7

array_reduce = 7

array_filter & count = 7

array_column & array_filter & count = 7

array_map & array_count_values & array_replace = 7

array_map & array_count_values = 7

photo値のないデータを使用した入出力（2番目のarray_count_values()方法で問題が発生）：

$array=[
    (object)['type'=>'status','id'=>1404781893036,'created_time'=>'2012-03-01T09:49:40+0000'],
    (object)['type'=>'status','id'=>14047818930362,'created_time'=>'2012-03-01T09:36:04+0000'],
    (object)['type'=>'status','id'=>1404781893036,'created_time'=>'2012-02-25T09:36:57+0000'],
    (object)['type'=>'status','id'=>1404781893036,'created_time'=>'2012-02-22T21:04:30+0000'],
    (object)['type'=>'status','id'=>1404781893036,'created_time'=>'2012-02-21T20:38:27+0000'],
    (object)['type'=>'status','id'=>14047818930362,'created_time'=>'2012-02-20T08:32:46+0000'],
    (object)['type'=>'status','id'=>1404781893036,'created_time'=>'2012-02-17T15:00:11+0000']
];
// or if there are no object rows like: $array=[];
// output:
foreach result = 0

array_reduce = 0

array_filter & count = 0

array_column & array_filter & count = 0

array_map & array_count_values & array_replace = 0

array_map & array_count_values (gives Notice) = <br />
<b>Notice</b>:  Undefined index: photo in <b>[...][...]</b> on line <b>43</b><br />

array_count_values()カウント付きの要素をわざわざ生成する必要はありません0。

于 2017-10-24T02:23:52.390 に答える
1

試してみてください：

$input = array( /* your data */ );
$count = 0;
foreach ( $input as $value ) {
  if ( $value->type == 'photo' ) {
    $count++;
  }
}
于 2012-03-07T10:09:14.490 に答える