如果你还没有完成Day01的内容，请先去了解喔!!

阶层

在我们新增座标点在地图上之前，我们需要了解到openlayers中的阶层问题如下

js

const map = new ol.Map({    layers: [        new ol.layer.Tile({            source: new ol.source.OSM()        })    ],    target: 'map',    view: new ol.View({        projection: "EPSG:3857",        center: ol.proj.fromLonLat([120.846642, 23.488793]),        zoom: 7.5,        maxZoom: 20,        minZoom: 5,        enableRotation: false,    }),    controls: []});# 这边要注意阶层与物件的新增let point = new ol.layer.Vector({    source: new ol.source.Vector({        features: [            new ol.Feature({                geometry: new ol.geom.Point(ol.proj.fromLonLat([121, 23]))            })        ]    })}); # 新增一个layer后别忘了加到地图中，我自己就常常忘记XDmap.addLayer(point);

参考连结

https://github.com/weijung0923/learning-openlayers-micromastery/tree/day02