>我有以下数组
Array (
[0] => Array
(
[0] => ALFA
[1] => 213
)
[1] => Array
(
[0] => ALFA
[1] => 151
)
[2] => Array
(
[0] => ALFA
[1] => 197
)
[3] => Array
(
[0] => BETA
[1] => 167
)
[4] => Array
(
[0] => ZETA
[1] => 254
)
[5] => Array
(
[0] => GAMA
[1] => 138
)
[6] => Array
(
[0] => GAMA
[1] => 213
)
)
我想对子数组的键[0]进行分组，以便我可以看到它有多少个相等的键。
像这样：
ALFA => 3
BETA => 1
EPSI => 1
GAMA => 2
我尝试了array_count_values，但没有成功。
foreach ($array as $value) {
echo '<pre>';
print_r(array_count_values($value));
echo '</pre>';
}
有了这个，我们得到以下结果：
Array
(
[ALFA] => 1
[213] => 1
)
Array
(
[ALFA] => 1
[151] => 1
)
...
Array
(
[GAMA] => 1
[213] => 1
)
之后，我还想对每个组的值求和。
ALFA => 213 + 151 + 197
BETA => 167
ZETA => 254
GAMA => 138 + 213
我认为，当我们解决问题的第一部分时，使用完全相同的方法，第二部分会更容易。
最终目的是将值的总和除以每个键组的出现次数，因此我们可以得到值的平均值，如下所示：
ALFA => (213+151+197) / 3 = 187
BETA => 167
ZETA => 254
GAMA => (138+213) / 2 = 175,5
这不是主要问题，但正如我所说，我坚持解决方案的开始，并希望得到任何帮助。
我对所有
冗长而复杂的答案感到惊讶。但是，需要初始 foreach 将数据建模为可管理的内容。之后，您只需要做一个非常简单的array_walk。
<?php
$result = array();
foreach ($array as $el) {
if (!array_key_exists($el[0], $result)) {
$result[$el[0]] = array();
}
$result[$el[0]][] = $el[1];
}
array_walk($result, create_function('&$v,$k', '$v = array_sum($v) / count($v);'));
?>
结果：
Array
(
[ALFA] => 187
[BETA] => 167
[ZETA] => 254
[GAMA] => 175.5
)
为您提供
的解决方案在这里：
法典：
$input = [
['alfa', 123],
['alfa', 223],
['alfa', 122],
['alfa', 554],
['alfa', 34],
['dalfa', 123],
['halfa', 223],
['dalfa', 122],
['halfa', 554],
['ralfa', 34]
];
$result = [];
foreach ($input as $node) {
if (isset($result[$node[0]])) {
$result[$node[0]] = ['sum' => $result[$node[0]]['sum'] + $node[1], 'count' => $result[$node[0]]['count'] + 1];
} else {
$result[$node[0]] = ['sum' => $node[1], 'count' => 1];
}
}
print_r($result);
foreach ($result as $key => &$data) {
$data = $data['sum'] / $data['count'];
}
print_r($result);
输出：
Array
(
[alfa] => Array
(
[sum] => 1056
[count] => 5
)
[dalfa] => Array
(
[sum] => 245
[count] => 2
)
[halfa] => Array
(
[sum] => 777
[count] => 2
)
[ralfa] => Array
(
[sum] => 34
[count] => 1
)
)
Array
(
[alfa] => 211.2
[dalfa] => 122.5
[halfa] => 388.5
[ralfa] => 34
)
$sort = array();
foreach ($array as $value) {
$sort[$value[0]][] = $value[1];
}
然后你数一数每个有多少键
$keys = array();
foreach($sort as $k => $v) {
$keys[$k] = count($v);
}
然后用于计算金额
$sum = array();
$average = array();
foreach($sort as $k => $v) {
$amount = 0;
foreach($v as $val) {
$amount += $val;
}
$sum[$k] = $amount;
$average[$k] = $amount / $keys[$k];
}
但是，如果您希望将所有详细信息放在一个数组中：
$final = array();
foreach ($array as $value) {
$final[$value[0]]["values"][] = $value[1];
}
foreach($final as $k => $v) {
$final[$k]["amount"] = count($v['values']);
$amount = 0;
foreach($v['values'] as $val) {
$amount += $val;
}
$final[$k]["sum"] = $amount;
$final[$k]["average"] = $amount / $final[$k]["amount"];
}
示例：http://jdl-enterprises.co.uk/sof/25789697.php
包括输出
只需将代码复制到您喜欢的文本编辑器中，即可确保它完美运行。
$items = [
['ALFA',213],
['ALFA',151],
['ALFA',197],
['BETA',167],
['ZETA',254],
['GAMA',138],
['GAMA',213]
];
echo '<pre>' . print_r($items,true) . '</pre>';
$result;
foreach ($items as $value) {
# code...
if (isset($result[$value[0]])) {
$sum = $result[$value[0]]['sum'] + $value[1];
$count = $result[$value[0]]['count'] + 1;
$result[$value[0]] = ['sum' => $sum , 'count' => $count, 'divided' => ($sum / $count)];
} else {
$result[$value[0]] = ['sum' => $value[1] , 'count' => 1 , 'divided' => ($value[1] / 1) ];
}
}
echo '<pre>' . print_r($result,true) . '</pre>';
$myArray = [
["ALFA",213],
["ALFA",151],
["ALFA",197],
["BETA",167],
["ZETA",254],
["GAMA",138],
["GAMA",213]
];
$a1 = array(); //TEMPORARY ARRAY FOR KEEPING COUNT & TOTAL VALUES
$res = array(); //ARRAY USED TO KEEP RESULT
foreach($myArray as $val)
{
//AVOID PESKY NOTICES FOR UNDEFINED INDEXES
if ( !array_key_exists($val[0],$a1) ) {
$a1[$val[0]] = array("count" => 0,"total" => 0);
$res[$val[0]] = 0;
}
//INCREMENT THE COUNT OF INSTANCES OF THIS KEY
$a1[$val[0]]["count"]++;
//INCREMENT THE TOTAL VALUE OF INSTANCES OF THIS KEY
$a1[$val[0]]["total"]+=$val[1];
// UPDATE RESULT ARRAY
$res[$val[0]] = $a1[$val[0]]["total"] / $a1[$val[0]]["count"];
}
print_r($res);
应导致：
Array
(
[ALFA] => 187
[BETA] => 167
[ZETA] => 254
[GAMA] => 175.5
)
示例：http://phpfiddle.org/lite/code/a7nt-5svf