$a = [
['goods_id'=>2,'num'=>4],
['goods_id'=>2,'num'=>5],
['goods_id'=>4,'num'=>6],
['goods_id'=>4,'num'=>6],
['goods_id'=>4,'num'=>6]
];
$b = [];
echo "<pre>";
print_r($a);
foreach( $a as $key=>$val ){
if( array_key_exists($val['goods_id'], $b) ){
$b[$val['goods_id']]['num'] += $val['num'];
}else{
$b[$val['goods_id']] = $val;
}
}
sort($b);
print_r($b);
['goods_id'=>2,'num'=>4],
['goods_id'=>2,'num'=>5],
['goods_id'=>4,'num'=>6],
['goods_id'=>4,'num'=>6],
['goods_id'=>4,'num'=>6]
];
$b = [];
echo "<pre>";
print_r($a);
foreach( $a as $key=>$val ){
if( array_key_exists($val['goods_id'], $b) ){
$b[$val['goods_id']]['num'] += $val['num'];
}else{
$b[$val['goods_id']] = $val;
}
}
sort($b);
print_r($b);