php数组整合

Question

 $arr=[
     ['id'=>1,'name'=>'php','num'=>3],
     ['id'=>2,'name'=>'js','num'=>1],
     ['id'=>1,'name'=>'php','num'=>2],
     ['id'=>3,'name'=>'python','num'=>2],
 ];
//怎么对id相同的对num求和并去重，返回的结果为
 $arr=[
     ['id'=>1,'name'=>'php','num'=>5],
     ['id'=>2,'name'=>'js','num'=>1],
     ['id'=>3,'name'=>'python','num'=>2],
 ];

Answer 1

$result = [];
foreach ($arr as $v) {
    if (isset($result[$v['id']])) {
        $result[$v['id']]['num'] += $v['num'];
    }
    else {
        $result[$v['id']] = $v;
    }
}
print_r($result);