How to Determine if Android Device Supports WiFi

public static final String FEATURE_WIFI was added in API level 8
Feature for getSystemAvailableFeatures() and hasSystemFeature(String).

The device supports WiFi (802.11) networking.
Constant Value: "android.hardware.wifi"

1. Get a PackageManager Instance named myPackageManager.

2. Create a Boolean Variable named bolWifiSupported. 

3. Set the Minimum and Target SDK version  to 8 or greater. 

4. In the onCreate method, add the below code. This will return the Wifi availability to a boolean named bolWifiSupported. It will then display a toast displaying the Wifi availability of the device to the user.

bolWifiSupported = myPackageManager.hasSystemFeature(PackageManager.FEATURE_WIFI);

if (bolWifiSupported) {

Toast.makeText(this, "Device supports Wifi", Toast.LENGTH_LONG).show();

} else {

Toast.makeText(this, "Device does NOT support Wifi!", Toast.LENGTH_LONG).show();

}

5. Compile and run!

Resources:
http://developer.android.com/reference/android/content/pm/PackageManager.html#FEATURE_WIFI