php数组多维计数和foreach答案

【问题标题】：php array multidimensional count and foreachphp数组多维计数和foreach
【发布时间】：2016-12-06 11:57:41
【问题描述】：

我有一个如下所示的数组：

Array ( 
[0] => Array ( 
    [Time] => 00 
    [Activity] => Surfing 
    ) 
[1] => Array ( 
    [Time] => 00 
    [Activity] => Surfing 
    ) 
[2] => Array ( 
    [Time] => 00 
    [Activity] => Kayaking 
    ) 
[3] => Array ( 
    [Time] => 15 
    [Activity] => Surfing 
    ) 
)

但我很难以正确的格式获得所需的计数。基本上我希望实现的是每个“时间”内每个“活动”的计数。因此，例如，我想输出如下内容：

Time:00 - Surfing 2; Kayaking 1
Time:15 - Surfing 1; Swimming 2
Time:45 - Surfing 1

等等

我不确定我应该查看计数函数还是 foreach 中的 foreach？但这让我很难过。提前致谢。

【问题讨论】：

你有什么尝试吗？
我看不到输入如何导致所需的输出...
你的问题不清楚。
@jeroen 和 pranav m.s - 请参阅下面的答案 ;-)
是的，我敢肯定“游泳”和“45”会像那样神奇地出现;-)

标签： php arrays multidimensional-array foreach

【解决方案1】：

我的尝试似乎奏效了：

$array = array(
    array("time"=>"00", "Activity"=>"Surfing"), 
    array("time"=>"00", "Activity"=>"Surfing"), 
    array("time"=>"00", "Activity"=>"Kayaking"), 
    array("time"=>"15", "Activity"=>"Surfing")
    );

$sortedArr = array();

/* first we need to sort the array so that we have a new array that is formatted with the time value as the key */

foreach($array as $arr) {

    $timeVal      = $arr['time'];
    $activityName = $arr['Activity'];

    /* if there is a time and activity key already set then we'll increment the count. Otherwise, we'll set it as 1 */

    if(isset($sortedArr[$timeVal][$activityName])) {
        $sortedArr[$timeVal][$activityName]++;
    } else {
        $sortedArr[$timeVal][$activityName] = 1;
    }
}

/* now we've re-ordered things, we'll build the output and then echo it out */

$output = '';
foreach($sortedArr as $key=>$vals) {
    $output.= 'Time:'.$key.' - ';

    foreach($vals as $activityName=>$activityCount) {
        $output .= $activityName.' '.$activityCount.';'.PHP_EOL;
    }
}

echo $output;

【讨论】：

这个似乎效果最好并且最灵活，所以我将其标记为答案。感谢大家的帮助！
谢谢，很高兴你喜欢我的回答。

【解决方案2】：

你可以试试：

$timings = [];
foreach ($array as $activity) {
    $timings[$activity['Activity']][] = $activity['Time'];
}

$surfing = array_sum($timings['Surfing']);

【讨论】：

【解决方案3】：

如果嵌套数组的结构不会改变你可以这样做：

$array = [
    [
        "Time" => "00",
        "Activity" => "Surfing"
    ],
    [
        "Time" => "00",
        "Activity" => "Surfing"
    ],
    [
        "Time" => "00",
        "Activity" => "Kayaking"
    ],
    [
        "Time" => "15",
        "Activity" => "Surfing"
    ]
];
$result = [];
foreach ($array as $key => $value) {
    $time = $value["Time"];
    $activity = $value["Activity"];
    if (!isset($result[$time])) {
        $result[$time] = [];
    }
    if (!isset($result[$time][$activity])) {
        $result[$time][$activity] = 0;
    }
    $result[$time][$activity]++;
}

结束print_r($result)返回这个：

Array
(
[00] => Array
    (
        [Surfing] => 2
        [Kayaking] => 1
    )

[15] => Array
    (
        [Surfing] => 1
    )

)

【讨论】：

【解决方案4】：

$new_array = array();
foreach ($array_list as $key => $val)
{
     if(isset($new_array[$val[$time]][$val['Activity']]))
     {
         $new_array[$val[$time]][$val['Activity']] += 1;
     }
     else
     {
         $new_array[$val[$time]][$val['Activity']] = 1;
     }
}

下一步，无论您再次循环 new_array 以显示所有数组，您选择的每个唯一时间的新数组，或者如果您需要它在新数据中进行比较，您可以直接访问新数组，如下所示

echo $new_array['00']['Surfing']

然后你会得到时间 00 的冲浪计数

祝你好运

【讨论】：

【解决方案5】：

我知道我迟到了，但这是我的代码。输出你想要的。

<?php

//mockup
$activities = array( 
                array( 
                        "Time"     => "00",
                        "Activity" => "Surfing",
                  ), 
                array( 
                        "Time"     => "00",
                        "Activity" => "Surfing",
                  ), 
                array( 
                        "Time"     => "00",
                        "Activity" => "Kayaking", 
                  ), 
                array( 
                        "Time"     => "15", 
                        "Activity" => "Surfing"
                    ), 
                array( 
                        "Time"     => "15", 
                        "Activity" => "Swimming"
                    ), 
                array( 
                        "Time"     => "15", 
                        "Activity" => "Swimming"
                    ), 
                array( 
                        "Time"     => "45", 
                        "Activity" => "Surfing"
                    )  
);

$reordered = array();

foreach($activities as $activity)
{
    foreach($activity as $key => $value)
    {
        //echo "$key => $value <br>";

        if($key=="Time")
        {
            $tmp_time = $value;
        }
        elseif($key=="Activity")
        {
            if(!isset($reordered[$tmp_time][$value]))
                $reordered[$tmp_time][$value]=1;
            else
            $reordered[$tmp_time][$value]++;
        }
    }
}


//var_dump($reordered);

$output='';

foreach($reordered as $key => $arr)
{
    $output.='Time:' . $key . ' - ';

    foreach($arr as $activityName=>$activityCount) 
    {
        $output.= $activityName.' '.$activityCount.'; ';
    }
    $output = rtrim($output,"; ");
    $output.=PHP_EOL;
}



echo $output;

/*

Time:00 - Surfing 2; Kayaking 1
Time:15 - Surfing 1; Swimming 2
Time:45 - Surfing 1

*/

【讨论】：