Java Concepts to Know Before Starting Selenium Automation
To begin your automation journey, it's important to have a
solid understanding of at least one basic programming language. With this
foundation, you can begin exploring more advanced topics, such as test
automation frameworks, API testing, and continuous integration/continuous
delivery (CI/CD) pipelines. At the initial stage of the automation journey,
it's recommended to focus on mastering the basics of programming and
familiarizing yourself with tools such as Selenium WebDriver and Appium.
To begin the automation journey, it's recommended to have a
basic understanding of Java concepts. This may include object-oriented
programming (OOP) principles, data types, control structures, and exception
handling. Once you have a solid foundation in these concepts, you can move on
to more advanced topics, such as Selenium WebDriver, TestNG, and Maven. Having
a strong grasp of Java basics is essential for building robust and maintainable
test automation frameworks.
I would suggest starting with the following Java topics to
begin your automation journey:
OOPS Concept, things you should know:
Oops (Object-oriented Programming) is a programming paradigm
that focuses on the use of objects and their interactions to design software
systems. Java is a popular object-oriented programming language, and here are
some key concepts of OOPs in Java:
Class: A class is a blueprint or a template for creating
objects. It defines the properties (attributes or fields) and behaviour
(methods) that objects of that class will have.
Object: An object is an instance of a class. It has its own
set of values for the attributes defined in the class, and it can perform the
methods defined in the class.
Inheritance: Inheritance is a mechanism that allows a class
to inherit the properties and methods of another class. The class that inherits
from another class is called a subclass or a derived class, and the class that
is inherited from is called a superclass or a base class.
Polymorphism: Polymorphism is the ability of an object to
take on many forms. In Java, polymorphism can be achieved through method
overloading and method overriding.
Encapsulation: Encapsulation is the process of hiding the
internal details of an object and providing a public interface to access and
manipulate it. It helps to achieve data abstraction, which means that the
implementation details are hidden from the outside world.
Abstraction: Abstraction is the process of hiding the
implementation details and providing a simplified interface for the users. In
Java, abstraction can be achieved through abstract classes and interfaces.
Method Overloading: Method overloading is the process of
defining multiple methods with the same name in a class, but with different
parameters. Java determines which method to call based on the number and type
of arguments passed.
Method Overriding: Method overriding is the process of
defining a method in a subclass with the same name and parameters as a method
in the superclass. When a method is called on an object of the subclass, the
overridden method in the subclass is executed instead of the method in the
superclass.
DataTypes in Java
In Java, there are two categories of data types:
Primitive data types:
Java has eight primitive data types that are used to
represent the basic types of data, such as numbers, characters, and boolean
values. These data types are:
byte: 8-bit signed integer
short: 16-bit signed integer
int: 32-bit signed integer
long: 64-bit signed integer
float: 32-bit floating-point number
double: 64-bit floating-point number
char: 16-bit Unicode character
boolean: true or false value
Reference data types:
Java has reference data types, which are used to refer to
objects. These data types are:
class types: class, interface, enum
array types: arrays of objects or primitives
interface types: interface references
Variables:
In Java, a variable is a named memory location that stores a
value of a particular data type. A variable is declared by specifying its name,
data type, and an optional initial value. Here's an example of how to declare a
variable in Java:
int age; // declares a variable named "age" of
type int
In this example, we declared a variable named
"age" of type int. The "int" data type represents a 32-bit
signed integer.
We can also initialize a variable with a value when it is
declared. Here's an example:
int age = 25; // declares a variable named "age"
of type int and initializes it with the value 25
In this example, we declared a variable named
"age" of type int and initialized it with the value 25.
We can also assign a value to a variable after it has been
declared. Here's an example:
age = 30; // assigns the value 30 to the "age" variable
In this example, we assigned the value 30 to the
"age" variable.
It's important to note that a variable's value can change
throughout the program's execution, but its data type cannot. Once a variable
is declared with a data type, it cannot be changed.
Also, Java is a statically typed language, which means that
variables must be declared with a data type before they can be used. This helps
catch type errors before the code is executed.
Operator:
Arithmetic operators:
Arithmetic operators are used to perform mathematical
operations on numeric values. Examples include + (addition), - (subtraction), *
(multiplication), / (division), and % (modulus).
Assignment operators:
Assignment operators are used to assign values to variables.
Examples include = (simple assignment), += (add and assign), -= (subtract and
assign), *= (multiply and assign), /= (divide and assign), and %= (modulus and
assign).
Comparison operators:
Comparison operators are used to compare values. Examples
include == (equal to), != (not equal to), > (greater than), < (less
than), >= (greater than or equal to), and <= (less than or equal to).
Logical operators:
Logical operators are used to combine and manipulate boolean
values. Examples include && (logical AND), || (logical OR), and !
(logical NOT).
Bitwise operators:
Bitwise operators are used to perform operations on
individual bits of numeric values. Examples include & (bitwise AND), |
(bitwise OR), ^ (bitwise XOR), ~ (bitwise complement), << (left shift),
and >> (right shift).
Conditional operator:
The conditional operator (?:) is a shorthand way of writing
an if-else statement. It is used to evaluate a boolean expression and return
one value if it is true and another value if it is false.
Increment and decrement operators:
Increment and decrement operators are used to increase or
decrease the value of a variable by 1. Examples include ++ (increment) and --
(decrement).
Decision Making Statements
In Java, decision-making statements allow you to control the
flow of your program based on certain conditions. Here are the three main types
of decision-making statements in Java:
if statement:
The if statement is used to execute a block of code if a
certain condition is true. If the condition is false, the code inside the if
statement is skipped.
if-else statement:
The if-else statement is used to execute one block of code
if a condition is true and another block of code if the condition is false.
switch statement:
The switch statement is used to execute different blocks of
code based on the value of a variable or expression.
Iterative Statements
In Java, iterative statements (also known as loops) allow
you to repeat a block of code multiple times. Here are the three main types of
iterative statements in Java:
for loop:
The for loop is used to repeat a block of code a specific
number of times. It consists of an initialization statement, a condition, and
an increment statement.
while loop:
The while loop is used to repeat a block of code as long as
a certain condition is true.
do-while loop:
The do-while loop is similar to the while loop, but it
guarantees that the code inside the loop is executed at least once.
Methods:
In Java, a method is a block of code that performs a
specific task and can be called and executed multiple times throughout a program.
Methods are used to organize code, reduce redundancy, and make code easier to
read and understand.
Arrays:
In Java, an array is a data structure that stores a
fixed-size, ordered collection of elements of the same type. Each element in
the array is identified by its index, which starts at 0.
Arrays in Java are very useful for storing and manipulating
collections of data, such as lists of numbers or strings. They are also
commonly used in algorithms and data structures.
Strings:
In Java, a string is a sequence of characters. Strings are
used to represent text, and they are one of the most commonly used data types
in Java.
Strings are immutable in Java, which means that once you
create a string, you cannot change its value. However, you can create a new
string by performing operations on an existing string.
In Java, access modifiers are keywords that are used to
control the visibility and accessibility of classes, methods, and variables
within a program. There are four types of access modifiers in Java:
Access modifiers:
public: A public class, method, or variable can be accessed
from anywhere in the program, including other packages.
private: A private class, method, or variable can only be
accessed from within the same class.
protected: A protected class, method, or variable can be
accessed from within the same class, subclasses, and within the same package.
default (also known as package-private): A class, method, or
variable without any access modifier (i.e., no access modifier keyword is used)
can be accessed from within the same package, but not from outside the package.
Access modifiers are used to ensure proper encapsulation and
prevent unwanted access to certain parts of a program. By using access
modifiers, you can control the level of abstraction and separation of concerns
in your program. It is considered a best practice to use the most restrictive
access modifier possible for each class, method, or variable to ensure proper
data hiding and encapsulation.
Wrapper Class:
In Java, a wrapper class is a class that provides a way to
use primitive data types (such as int, float, boolean, etc.) as objects.
Wrapper classes are used to provide a richer set of methods and functionalities
for working with primitive data types.
There are eight wrapper classes in Java:
Byte: Wraps a byte value in an object.
Short: Wraps a short value in an object.
Integer: Wraps an int value in an object.
Long: Wraps a long value in an object.
Float: Wraps a float value in an object.
Double: Wraps a double value in an object.
Boolean: Wraps a boolean value in an object.
Character: Wraps a char value in an object.
Wrapper classes are often used when working with collections
(such as ArrayLists) and when passing values as objects (for example, when
using Java generics). They provide methods for converting between primitive
data types and objects, parsing strings to primitive data types, and performing
arithmetic and logical operations.
Exception handling:
Exception handling is a mechanism in Java that allows a
programmer to handle runtime errors and exceptions in a program in a structured
and controlled way.
When a program encounters an exception, it creates an object
representing that exception and throws it, which stops the normal execution of
the program. To handle the exception, the programmer can write code that
catches the exception and handles it gracefully.
File Handling:
File handling in Java allows you to read and write data to
and from files. Java provides several classes for file handling, including the
File, FileReader, FileWriter, BufferedReader, and BufferedWriter classes.
Collection Framework:
The Collection Framework in Java is a set of classes and
interfaces that provides a way to store and manipulate collections of objects.
It provides a unified architecture for representing and manipulating collections,
making it easy to work with different types of collections, such as lists,
sets, and maps.
We will be going in-depth of each topic in coming blogs.
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