Determine if Lat/Lng in Bounds

I’m interested in determining if a lat/lng location is within the bounds and looking for recommendations on a algorithm. (javascript or php)

Here is what I have so far:

var lat = somelat;
var lng = somelng;

if (bounds.southWest.lat < lat && lat < bounds.northEast.lat && bounds.southWest.lng < lng && lng < bounds.northEast.lng) {
     'lat and lng in bounds
}

will this work? thanks

Answer

The simple comparison in your post will work for coordinates in the US. However, if you want a solution that’s safe for checking across the International Date Line (where longitude is ±180°):

function inBounds(point, bounds) {
    var eastBound = point.long < bounds.NE.long;
    var westBound = point.long > bounds.SW.long;
    var inLong;

    if (bounds.NE.long < bounds.SW.long) {
        inLong = eastBound || westBound;
    } else {
        inLong = eastBound && westBound;
    }

    var inLat = point.lat > bounds.SW.lat && point.lat < bounds.NE.lat;
    return inLat && inLong;
}