Where is the 'string.xml'?

[lianjianjie]

[faizanMayo786]

Createstring.xmlunderres/valuesDirectory and add this code to it.

<?xml version="1.0" encoding="utf-8"?>
<resources>
<!-- Replace "343254889799245" with your Facebook App ID here. -->
    <string name="facebook_app_id">343254889799245</string>
</resources>

Hope this will help you.