Interview Question for Intermediate level
What is Persistent and
Non-Persistent object in android?
Ans:-
Persistent Objects:- an application appears to continue running, the
system may choose to kill its process and restart it later.
For
sharing complex persistent user-defined objects, the following approaches are
recommended:
·
Application
Preferences
·
Files
·
contentProviders
·
SQLite
DB
Non-Persistent
object:
For
sharing complex non-persistent user-defined objects for short duration, the
following approaches are recommended:
What is portable Wi-Fi hotspot?
Ans:
The portable Wi-Fi® hotspot feature allows you to share
your mobile device’s data connection with other devices by turning your device
into a wireless access point. You can connect up to 8 wireless devices via
Wi-Fi.
What is the difference between
a regular bitmap and a nine-patch image?
Ans:
It is one of a resizable bitmap resource which is
being used as backgrounds or other images on the device. The NinePatch class
allows drawing a bitmap in nine sections. The four corners are unscaled; the
middle of the image is scaled in both axes, the four edges are scaled into one
axis.
Explain about the
exceptions of Android?
Ans.
What is ,dex extension.
What is the significance of the .dex files?
Ans.
Android programs are compiled into .dex (Dalvik
Executable) files, which are in turn zipped into a single .apk file on the
device. .dex files can be created by automatically translating compiled
applications written in the Java programming language
What is the difference between
Service and Thread?
Ans:
·
Service
is like an Activity but has no interface. Probably if you want to fetch the
weather for example you won't create a blank activity for it, for this you will
use a Service.
·
A Thread is a Thread, probably you
already know it from other part. You need to know that you cannot update UI from
a Thread. You need to use a Handler for this, but read further.
·
An AsyncTask is an intelligent Thread
that is advised to be used. Intelligent as it can help with it's methods, and
there are two methods that run on UI thread, which is good to update UI
components
What is the importance
of XML-based layouts?
Ans:
The use of
XML-based layouts provides a consistent and somewhat standard means of setting
GUI definition format. In common practice, layout details are placed in XML
files while other items are placed in source files.
What is the importance
of settings permissions in app development in Android?
Ans:
Permissions allow certain restrictions to be imposed
primarily to protect data and code. Without these, codes could be compromised,
resulting to defects in functionality.
What is an URIs?
Ans:
An uniform
resource identifier (URI) is a string of characters used to identify a name of a web resource
A URI reference includes a URI and a fragment, the
component of the URI following a '#'. Builds and parses URI references which
conform to RFC 2396.
Can I write code for
Android using C/C++?
Ans:
Yes, using NDKyou can write but
it too complex so avoid this.
Does Android support
the Bluetooth serial port profile?
Ans:
The most common type of Bluetooth socket is RFCOMM,
which is the type supported by the Android APIs. RFCOMM is a
connection-oriented, streaming transport over Bluetooth. It is also known as
the Serial Port Profile (SPP).
How to select more than
one option from list in android xml file?
Specify android id, layout height and
width as depicted in the following example.
What is Mono in
Android?
Ans:
Mono is a free
and open source project
led by Xamarin (formerly by Novell and
originally by Ximian) to create
an Ecma standard-compliant, .NET Framework-compatible set of tools including, among others, a C# compiler and a Common
Language Runtime.
What are the differences between
a domain and a workgroup?
Ans:
In a domain, one or
more computer can be a server to manage the network. On the other hand in a
workgroup all computers are peers having no control on each other. In a domain,
user doesn’t need an account to logon on a specific computer if an account is
available on the domain. In a work group user needs to have an account for
every computer.
In a domain, Computers can be on different local networks. In a work group all computers needs to be a part of the same local network.
In a domain, Computers can be on different local networks. In a work group all computers needs to be a part of the same local network.
Explain IP datagram,
Fragmentation and MTU.
Ans:
IP datagram can be used to describe a portion of IP data.
Each IP datagram has set of fields arranged in an order. The order is specific
which helps to decode and read the stream easily. IP datagram has fields like
Version, header length, Type of service, Total length, checksum, flag,
protocol, Time to live, Identification, source and destination ip address,
padding, options and payload.
MTU:-
Maximum Transmission Unit is the size of the largest packet that a
communication protocol can pass. The size can be fixed by some standard or
decided at the time of connection
Fragmentation
is a process of breaking the IP packets into smaller pieces. Fragmentation is needed
when the datagram is larger than the MTU. Each fragment becomes a datagram in
itself and transmitted independently from source. When received by destination
they are reassembled.
Why Activitylife cycle is must. What are the Different phases of
Activity Life cycle. For example: when and how the activity comes to
foreground?
The square
rectangles represent callback methods you can implement to perform operations
when the Activity moves between states. The colored ovals are major states the
Activity can be in.
