目前，我有一个搜索栏，它将用户的搜索查询保存在cookie中。为此，我将用户的所有输入保存在一个数组中。现在的问题是，如果用户再次键入相同的内容，它将被复制，并将复制的值保存在数组中。我希望有一种方法，使复制的值不会添加到已设置的cookie中：

$input_search = json_decode(($this->input->post('keyword_search')));

    if(isset($input_search))
    foreach($input_search as $searchvals){
        $searchvals->name = $searchvals->value;
        unset($searchvals->value);
        $searchval = json_encode($searchvals);

        if (!isset($_COOKIE['lpsearch_history'])){  
                setcookie('lpsearch_history',$searchval,time() +3600 *365,'/'); 
            }else {
                $locations[] = json_decode($_COOKIE['lpsearch_history'], true);
                $arrsearchval = json_decode($searchval, true);
                if(!in_array($arrsearchval, $locations))
                    $locations[] = $arrsearchval;
                $areas = json_encode($locations);
                setcookie('lpsearch_history',$areas,time() +3600 *365,'/');
            }
    }

现在，它会给出如下输出：

[[[[{"type":"community","devslug":"downtown-dubai","name":"Downtown Dubai"}],
{"type":"community","devslug":"downtown-dubai","name":"Downtown Dubai"}],    
{"type":"community","devslug":"palm-jumeirah","name":"Palm Jumeirah"}],    
{"type":"community","devslug":"palm-jumeirah","name":"Palm Jumeirah"}]