PHP 数组中如果有一个元素相同，如何拼接其他元素
比如原数组是这样的
array(3) {
[0] => array(6) {
["pla_id"] => string(3) "298"
["user_id"] => string(1) "1"
["due_in"] => string(15) "8.33"
}
[1] => array(6) {
["pla_id"] => string(3) "976"
["user_id"] => string(1) "1"
["due_in"] => string(15) "338.90"
}
[2] => array(6) {
["pla_id"] => string(3) "56"
["user_id"] => string(1) "2"
["due_in"] => string(15) "25.6"
}}
因为数组中的user_id=1 是一样的
要得到最后这样数组，要怎么写(就是把user_id相同的其他元素拼接在一起)？
array(3) {
[0] => array(6) {
["pla_id"] => string(3) "298,976"
["user_id"] => string(1) "1"
["due_in"] => string(15) "8.33,338.90"
}
[1] => array(6) {
["pla_id"] => string(3) "56"
["user_id"] => string(1) "2"
["due_in"] => string(15) "25.6"
}}
------解决思路----------------------
$a = array(<br> array(<br> "pla_id" => "298",<br> "user_id" => "1",<br> "due_in" => "8.33",<br> ),<br> array(<br> "pla_id" => "976",<br> "user_id" => "1",<br> "due_in" => "338.90",<br> ),<br> array(<br> "pla_id" => "56",<br> "user_id" => "2",<br> "due_in" => "25.6",<br> )<br>);<br>$b = array();<br>foreach($a as $v) {<br> if(! isset($b[$v['user_id']])) $b[$v['user_id']] = $v;<br> else $b[$v['user_id']]["due_in"] .= ',' . $v["due_in"];<br>}<br>var_dump(array_values($b));array(2) {<br> [0]=> array(3) {<br> ["pla_id"]=> string(3) "298"<br> ["user_id"]=> string(1) "1"<br> ["due_in"]=> string(11) "8.33,338.90"<br> }<br> [1]=> array(3) {<br> ["pla_id"]=> string(2) "56"<br> ["user_id"]=> string(1) "2"<br> ["due_in"]=> string(4) "25.6"<br> }<br>}<br><br>
