當標記之一是 null 經度和緯度時，leaflet map 不顯示所有標記

Question

I recently get a task from my School, I made a simple map using leaflet, but I have a problem, the marker from my map doesn't show, when one of the markers get null on longitude and latitude from the database, I Want我的 map 中的另一個標記仍然有效，甚至其中一個標記得到 null 經度和緯度:) 這是我的一些代碼：

            while($row = mysqli_fetch_assoc($data)) {
            if($row['latitude'] == 0 ){

                // what should i do here, ????
                // var_dump('place_name');

            }else{

            // add marker to map
            $marker .= 'var marker = L.circle(['.$row['latitude'].', '.$row['longitude'].'],
            {
                color: "red",
                fillColor: "#f03",
                fillOpacity: 0.5,
                radius: 2000
            }
            ).addTo(map).bindPopup("'.$row['place_name'].'").openPopup().on("mouseover", function (e) {
                this.openPopup();
            }).on("mouseout", function (e) {
                this.closePopup();
            });
            ;
            ';
        }

    }

有人可以給我一些建議來解決這個問題嗎？謝謝閱讀：）

Answer 1

你可以嘗試這樣的事情來跳過 null 緯度和經度：

while ($row = mysqli_fetch_assoc($data)) {
    $latitude = (float)$row['latitude'];
    $longitude = (float)$row['longitude'];

    if ($latitude === 0 && $longitude === 0) {
        continue;
        // what should i do here, ????
        // var_dump('place_name');
    }

    // add marker to map
    $marker .= sprintf('var marker = L.circle([ %s, %s],
            {
                color: "red",
                fillColor: "#f03",
                fillOpacity: 0.5,
                radius: 2000
            }
            ).addTo(map).bindPopup("%s").openPopup().on("mouseover", function (e) {
                this.openPopup();
            }).on("mouseout", function (e) {
                this.closePopup();
            });
            ;
            ', $latitude, $longitude, $row['place_name']);
}

:)