Java Interview Questions and Answers Video Lecture | Selenium Test Automation:Tutorial for Beginners (English) - Software Testing

say Java interview questions general
questions what is Java Java is a
programming language and a platform
software platform we have two types of
platforms in compute environment
one is Hardware plot from another is
software platform Java provides software
platform Java is a programming language
and a platform Java is used as a
programming language to develop software
applications next Java is used as
software platform to run Java
applications next water important Java
additions are parts of Java Java has
three important additions one is Java
standard edition our core Java core Java
is public Tom but official Tomas Java
standard edition our core Java world
name is J 2 EA c java 2 standard edition
that is holdin a new name Java standard
edition first edition Java standard
edition next Java Enterprise Edition our
advanced java world name Jawad 2
Enterprise Edition j2e
next third one Java micro edition old
name is j2me Java 2 micro edition it is
for small devices like Mobile's
Java standard edition Java Enterprise
Edition
Java micro Edition next what where Java
is used where Java is used Java is used
to create desktop applications web
applications enterprise applications
mobile applications smart cards embedded
software scientific applications
computer games etc Java is used to
create desktop applications web
applications enterprise applications
mobile applications smart cards embedded
systems scientific applications game
software etc next how Java is used Java
is an open source software and platform
independent for software development
download and install JDK software JDK
Java development kit it includes JRE and
JVM Java Runtime environment and Java
Virtual Machine C for software
development download and install JDK
software next for runtime runtime means
to run software applications that
developed in Java for runtime download
and install JRE Java Runtime environment
software it includes JVM we can run Java
bytecode on any supported platform next
what are important features of Java
important features of Java are simple
Java is simple language next
object-oriented platform-independent
secured robust architecture neutral
portable interpreted multi-threaded and
distributed these are the important
features of Java simple object-oriented
platform independent secured robust
architectural neutral portable
interpreted multi-threaded and
distributed next what is JVM see Java
software three types three important
software's JVM JRE and JDK first what is
JVM java virtual machine is the virtual
machine that ronda java bytecodes the
JVM doesn't understand Java source code
that is why you compile your dot Java
files to obtain dot class files you
compile your Java files to obtain class
files that contain the byte codes
understandable by the JVM JVM can
understand class files not Java source
files okay next what is JRE
the java runtime environment provides
the libraries the java virtual machine
and other components to run applets and
applications written in the
our programming language Java Runtime
environment provides libraries Java
Virtual Machine and other components to
run Java applications and applets
written in the Java programming language
next what is jdk Java development kit is
a superset of JRE
is the superset of the JRE and contains
everything that is in the JRE plus tools
such as the compilers and debuggers
necessary for developing applications
and applets Java development kit is a
superset of JRE and contains everything
that is in the JRE plus tools such as
compilers and debuggers necessary for
developing applications and applets next
what are important Java language
elements important Java language
elements are data types modifiers
variables operators flow control
statements methods etc next what are the
fundamentals of whoops object-oriented
programming system for fundamentals of
object-oriented programming are one is
inheritance next polymorphism third one
abstraction fourth one encapsulation
inheritance polymorphism abstraction
and encapsulation are the fundamentals
of object-oriented programming next what
are Java syntax rules Java syntax rules
Java syntax rules are a first one Java
is a case since two language
case-sensitive
for example vbscript is not
case-sensitive no difference between
uppercase and lowercase letters in
vbscript but Java is a case since two
language next first two letter of class
name should be in uppercase next method
names should start with lowercase letter
next Java program file name should
exactly match with class name next Java
program execution starts from main
method which is mandatory in every Java
program next every statement our step
should end with semicolon next code
blocks and closed with curly braces code
blocks conditional blocks loop blocks
method blocks etc code blocks enclosed
with curly braces next how to setup Java
environment on windows operating system
how to setup Java environment C in order
to write and execute Java programs we
need to setup Java environment for
example if we are using Windows
operating system first download Java
software JDK Java development kit and
install download
edek a software from either java.com or
oracle.com and install next set
environment variable path path variable
next download Eclipse IDE and extract
next launch Eclipse IDE write java
program and execute next how to set
environment variable path in Windows
operating environment say after Java
installation JDK installation then you
can get Java folder in c program files
set an environment variable path how to
set navigation first take JDK bin
directory path select my computer and
right-click properties advanced system
settings environment variables select
path variable from system variables edit
paste Java bin directory path in
variable value field ok ok ok close next
how to write and execute java programs
using windows command prompt without
eclipse ide how to write and execute
java programs using windows command
prompt in computer programming we have
three steps write program next compile
the program next third one execute the
program this is for any computer program
not only Java
write a program compile the program and
execute our on the program executes on
synonyms a first step write a sample
program in notepad and save with Java
extension next step to compile the
program
launch command prompt change to change
directory change to Java program file
directory suppose my Java program file
available on desktop change to desktop
next type javac jav a c java c c c4
compiler type javac next space program
file name dot java for example sample
dot java
it creates Java class file launch
command prompt change to Java program
file directory type Java C and program
name dot Java
it creates Java class file next third
step run or execute the program from
command prompt type Java and program
name no extension required type Java
space program name program file name
then it displays the output on the
console then it displays the output on
the console ok next what is Eclipse IDE
Eclipse IDE ID stands for integrated
development environment Eclipse IDE is a
platform to write and execute computer
programs like Java Perl Python Ruby PHP
etc it
not only for Java it is for all popular
computer programs Eclipse IDE is a
platform open-source to write and
execute computer programs like Java
parallel Python Ruby PHP excetera
Eclipse IDE is open source it provides
editor for writing programs syntax
guidance context health and auto
compilation Xsara note using Eclipse IDE
we can write and execute Java programs
next how to write and execute java
programs using Eclipse IDE steps to
write and execute a Java program using
Eclipse IDE first launch Eclipse IDE
create Java project it is one-time
activity next create Java package under
the Java project next create Java class
first create Java project under Java
project create Java package under the
java package create java class one or
more classes one by one Java project
Java package Java class this is the
hierarchy write Java program and run
Eclipse IDE provides auto compilation
facility next explain about Java program
structure see sections of Java program
first documentation section it is
optional view write meaningful
documentation
that is useful for users documentation
section optional next package
declaration statement third one import
statements one or more you can import
predefined it and the user definer
libraries using import keyword next
fourth one class declaration statement
fifth one main method Java program
execution starts from main method next
declarations we declare variables and
constants in our programs
next seventh one general statements
eighth one code blocks conditional
blocks condition blocks loop blocks and
others condition blocks loop blocks etc
see documentation section package
declaration statement import statements
for normal class declaration main method
next variables and constants declaration
general statements are normal statements
code blocks okay every normal statement
should end with semicolon and every code
block enclosed with curly braces thank
you