This example creates circles on the map, representing populations in North America.
Read the documentation.
TypeScript
// This example creates circles on the map, representing populations in North
// America.
// First, create an object containing LatLng and population for each city.
interface City {
center: google.maps.LatLngLiteral;
population: number;
}
const citymap: Record<string, City> = {
chicago: {
center: { lat: 41.878, lng: -87.629 },
population: 2714856
},
newyork: {
center: { lat: 40.714, lng: -74.005 },
population: 8405837
},
losangeles: {
center: { lat: 34.052, lng: -118.243 },
population: 3857799
},
vancouver: {
center: { lat: 49.25, lng: -123.1 },
population: 603502
}
};
function initMap(): void {
// Create the map.
const map = new google.maps.Map(
document.getElementById("map") as HTMLElement,
{
zoom: 4,
center: { lat: 37.09, lng: -95.712 },
mapTypeId: "terrain"
}
);
// Construct the circle for each value in citymap.
// Note: We scale the area of the circle based on the population.
for (const city in citymap) {
// Add the circle for this city to the map.
const cityCircle = new google.maps.Circle({
strokeColor: "#FF0000",
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: "#FF0000",
fillOpacity: 0.35,
map,
center: citymap[city].center,
radius: Math.sqrt(citymap[city].population) * 100
});
}
}
JavaScript
const citymap = {
chicago: {
center: { lat: 41.878, lng: -87.629 },
population: 2714856
},
newyork: {
center: { lat: 40.714, lng: -74.005 },
population: 8405837
},
losangeles: {
center: { lat: 34.052, lng: -118.243 },
population: 3857799
},
vancouver: {
center: { lat: 49.25, lng: -123.1 },
population: 603502
}
};
function initMap() {
// Create the map.
const map = new google.maps.Map(document.getElementById("map"), {
zoom: 4,
center: { lat: 37.09, lng: -95.712 },
mapTypeId: "terrain"
});
// Construct the circle for each value in citymap.
// Note: We scale the area of the circle based on the population.
for (const city in citymap) {
// Add the circle for this city to the map.
const cityCircle = new google.maps.Circle({
strokeColor: "#FF0000",
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: "#FF0000",
fillOpacity: 0.35,
map,
center: citymap[city].center,
radius: Math.sqrt(citymap[city].population) * 100
});
}
}
CSS
HTML
<!DOCTYPE html>
<html>
<head>
<title>Circles</title>
<script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
<script
src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap&libraries=&v=weekly"
defer
></script>
<link rel="stylesheet" type="text/css" href="./style.css" />
<script src="./app.js"></script>
</head>
<body>
<div id="map"></div>
</body>
</html>
All
<!DOCTYPE html>
<html>
<head>
<title>Circles</title>
<script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
<script
src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&callback=initMap&libraries=&v=weekly"
defer
></script>
<style type="text/css">
/* Always set the map height explicitly to define the size of the div
* element that contains the map. */
#map {
height: 100%;
}
/* Optional: Makes the sample page fill the window. */
html,
body {
height: 100%;
margin: 0;
padding: 0;
}
</style>
<script>
"use strict";
const citymap = {
chicago: {
center: {
lat: 41.878,
lng: -87.629
},
population: 2714856
},
newyork: {
center: {
lat: 40.714,
lng: -74.005
},
population: 8405837
},
losangeles: {
center: {
lat: 34.052,
lng: -118.243
},
population: 3857799
},
vancouver: {
center: {
lat: 49.25,
lng: -123.1
},
population: 603502
}
};
function initMap() {
// Create the map.
const map = new google.maps.Map(document.getElementById("map"), {
zoom: 4,
center: {
lat: 37.09,
lng: -95.712
},
mapTypeId: "terrain"
}); // Construct the circle for each value in citymap.
// Note: We scale the area of the circle based on the population.
for (const city in citymap) {
// Add the circle for this city to the map.
const cityCircle = new google.maps.Circle({
strokeColor: "#FF0000",
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: "#FF0000",
fillOpacity: 0.35,
map,
center: citymap[city].center,
radius: Math.sqrt(citymap[city].population) * 100
});
}
}
</script>
</head>
<body>
<div id="map"></div>
</body>
</html>
"use strict";
const citymap = {
chicago: {
center: {
lat: 41.878,
lng: -87.629
},
population: 2714856
},
newyork: {
center: {
lat: 40.714,
lng: -74.005
},
population: 8405837
},
losangeles: {
center: {
lat: 34.052,
lng: -118.243
},
population: 3857799
},
vancouver: {
center: {
lat: 49.25,
lng: -123.1
},
population: 603502
}
};
function initMap() {
// Create the map.
const map = new google.maps.Map(document.getElementById("map"), {
zoom: 4,
center: {
lat: 37.09,
lng: -95.712
},
mapTypeId: "terrain"
}); // Construct the circle for each value in citymap.
// Note: We scale the area of the circle based on the population.
for (const city in citymap) {
// Add the circle for this city to the map.
const cityCircle = new google.maps.Circle({
strokeColor: "#FF0000",
strokeOpacity: 0.8,
strokeWeight: 2,
fillColor: "#FF0000",
fillOpacity: 0.35,
map,
center: citymap[city].center,
radius: Math.sqrt(citymap[city].population) * 100
});
}
}
/* Always set the map height explicitly to define the size of the div
* element that contains the map. */
#map {
height: 100%;
}
/* Optional: Makes the sample page fill the window. */
html,
body {
height: 100%;
margin: 0;
padding: 0;
}
<!DOCTYPE html>
<html>
<head>
<title>Circles</title>
<script src="https://polyfill.io/v3/polyfill.min.js?features=default"></script>
<script
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyCb1xprYSpXd0q_yDsJ1W2UGhfl9_YGKU0&callback=initMap&libraries=&v=weekly"
defer
></script>
<!-- jsFiddle will insert css and js -->
</head>
<body>
<div id="map"></div>
</body>
</html>