急贴 将以下数组转换成相应格式的数组

Question

$arr = array(
0=>array("city"=>"上海","name"=>"A"),
1=>array("city"=>"北京","name"=>"B"),
2=>array("city"=>"上海","name"=>"C"),
3=>array("city"=>"长春","name"=>"C"),
4=>array("city"=>"沈阳","name"=>"A"),
5=>array("city"=>"北京","name"=>"A")
);
$new_arr = array(
0=>array("city"=>"上海,沈阳,北京","name"=>"A"),
1=>array("city"=>"北京","name"=>"B"),
2=>array("city"=>"上海,长春","name"=>"C"),
);

Answer 1

$arr = array(
0=>array("city"=>"上海","name"=>"A"),
1=>array("city"=>"北京","name"=>"B"),
2=>array("city"=>"上海","name"=>"C"),
3=>array("city"=>"长春","name"=>"C"),
4=>array("city"=>"沈阳","name"=>"A"),
5=>array("city"=>"北京","name"=>"A")
);
foreach ($arr as $key => $row) {
    $a[$row['name']][] = $row['city'];
}$b = array();
foreach ($a as $key=>$value)
{
    $b[] = array('city'=>implode(',',$value),'name'=>$key);
}
var_export($b);
应该不是最优的，凑合着用吧

Answer 2

<?php  
$arr = array(
0=>array("city"=>"上海","name"=>"A"),
1=>array("city"=>"北京","name"=>"B"),
2=>array("city"=>"上海","name"=>"C"),
3=>array("city"=>"长春","name"=>"C"),
4=>array("city"=>"沈阳","name"=>"A"),
5=>array("city"=>"北京","name"=>"A")
);
$flag = false;
$new_arr = array();
foreach ($arr as $value) {
$flag = false;
if(count($new_arr)==0) {
$new_arr[] = $value;
} else {
foreach ($new_arr as $key=>$new_value) {
if($value['name'] == $new_value['name']) {
$new_arr[$key]['city'] = $value['city'].','.$new_value['city'];
$flag = true;
}
}
if($flag == false) {
$new_arr[] = $value;
}
}
}