UNIT – 2 Features of java- (Shilpa R).pptx

CONTENTS
• Data Types
• Variables
• Operators & Expressions
• Decision making &
Branching
• if; if..else; nested if;
switch;
• ?:operator;
• Looping: while; do;
• For loop
• Arrays 2

3
Java Tokens: The tokens are the basic building blocks of the java
language. All the characters of java programs are grouped into
symbols called tokens.
There exists 6 java tokens:
• Identifier
• Keyword
• Separator
• Operators
• Literals
• Comment

4
JAVA TOKENS
Identifiers: they are used to identify variables, methods, classes and objects,
etc,. They are case sensitive.
Keywords: The keywords are words and names reserved for the java language.
Keywords appear in lowercase and cannot be used as identifiers. As of the latest
versions of Java, there are 54 reserved keywords Example: Boolean, break, class,
public, return etc.
Operators: The operators are symbols that represent operations. They operate
on operands and return results.
Separators: The separators are used by the java compiler to divide a program
into segments. Example: “,” “;”and “{ }”.
Literals: The literals are specific types of data explicitly entered into the code.
Comments: The comments are non-executable code.

5
// This is a simple Java program
public class SimpleProgram // Define a public class named SimpleProgram
{
public static void main(String[] args) // Main method - entry point of the program
{
// Declare and initialize variables
int num1 = 10; // integer literal
Int num2=20;
Int sum=num1+num2;// double literal
String message = "Hello, Java!"; // string literal
// Print the values of the variables
System.out.println(“Sum is: " + sum); // Concatenation operator (+)
System.out.println("Message: " + message); // Concatenation operator (+)
}
}

INTEGERS
The data types in Java are primarily divided into primitive and non-
primitive:
Primitive data types: Integers; Float; Characters; Boolean.
Integer: Java defines 4 integer types: byte; short; int; long.
Byte: byte is a primitive data type used to store integer values with a
small range.
Short: it is a primitive data type used to store integer values with a
slightly larger range than byte.
Int: it is a primitive data type used to store integer values.
long : it is a primitive data type used to store very large integer values.
Size: long occupies 64 bits (8 bytes) of memory.
8

Data Type Size Range Usage Example
byte 8 bits (1 byte) -128 to 127
Small ranges of
integers, memory-
efficient arrays
byte myByte = 100;
short 16 bits (2 bytes) -32,768 to 32,767
Larger ranges than
byte, more efficient
than int for large
arrays
short myShort =
10000;
int 32 bits (4 bytes)
-2,147,483,648 to
2,147,483,647
Default choice for
integer arithmetic
and calculations
int myInt = 100000;
long 64 bits (8 bytes) - 9,223,372,036,854,7
75,808 to
9,223,372,036,854,7
75,807
Very large integers,
especially useful for
calculations
requiring large
numbers
long myLong =
10000000000L;

10
Float: it is a primitive data type used to store single-precision floating-
point numbers.
Double: it is a primitive data type used to store double-precision
floating-point numbers.
FLOATING POINT TYPES
Data Type Size Range Precision Usage Example
float 32 bits (4
bytes)
Approximately
1.4e-45 to 3.4e+38
~7 decimal
digits
For single-precision
floating-point
numbers, more
memory-efficient
than double
float myFloat =
3.14f;
double 64 bits (8
bytes)
Approximately 4.9e-
324 to 1.8e+308
~15-16
decimal digits
For double-precision
floating-point
numbers, used when
higher precision is
needed
double
myDouble =
3.14159;

11
NON-NUMERIC DATA TYPES
Boolean Data Type- The Boolean data type is used to store only two possible values: true and
false.
This data type is used for simple flags that track true/false conditions.
Char Data Type - The char data type is used to store characters.
Data Type Size Range Precision Usage Example
boolean 1 byte No range; only
true or false
Not applicable For
representing
true/false
values and
making
decisions
boolean isRainy
= false;
char 2 bytes (16 bits) 0 to 65,535
(Unicode
characters)
Precise to a
single character
For storing and
manipulating
individual
characters
char grade = 'A';

VARIABLES
Variable- Variable is name of reserved area allocated in memory. It is a combination
of "vary + able" that means its value can be changed. Thr variables provide
mechanism to store data inside of a program.
Syntax: <datatype> <variablename>;
<datatype> <variablename>=value;
Eg: int data=50;
Types of Variables -There are three types of variables in java:
•local variable
•instance variable
•static variable
12

13
Example:
class A
{
int data=50; //instance variable
static int m=100; //static variable
void method()
{
int n=90; //local variable
}
}

14
TYPE CASTING
Casting is a process of converting one variable of certain data type into another
data type.
Types: Implicit casting & Explicit casting
Implicit casting: Automatic casting done by the java complier internally. It is
done to convert lower data type to higher data type(widening).
Eg: int i;
float f;
i=10;
f=i; //assign an int to float
Explicit casting: The casting is done by the java programmer or developer. It is
used for converting a higher data type to a lower data type(narrowing).
Eg: double d=6.289; double d=6.289;
int i=d; //error int i = int(d); //using explicit cast

OPERATORS
In Java, operators are symbols that perform operations on variables and values. They are
essential for manipulating data and performing calculations.
Unary operators: Unary operators in Java are operators that operate on a single operand.
They are used to perform operations such as incrementing, decrementing, negating, or
inverting values.
15

16
Arithmetic Operators: Arithmetic operators are symbols used in programming to perform
basic mathematical operations on numerical values. In Java, the arithmetic operators allow
you to carry out various calculations, such as addition, subtraction, multiplication, and
more

17
Relational Operators: Relational operators in Java are used to compare two values or
expressions. These operators return a boolean result (true or false) based on the
comparison. They are often used in conditional statements and loops to control the flow of
the program.

18
Assignment Operators: Assignment operators in Java are used to assign values to variables.
The most basic assignment operator is the single equals sign (‘=‘) which assigns the value on
the right to the variable on the left. However, Java also provides several compound
assignment operators that combine assignment with other operations.

19
Logical Operators: Logical operators in Java are used to perform logical operations on
boolean values. They are typically used in conditional statements and control flow constructs,
such as ‘if’,’while’,’for’.

20
Bitwise Operators: A bitwise operator is a type of operator that directly manipulates
bits, the basic units of data in computing, by performing operations on binary
representations of integers. Bitwise operations are commonly used in programming for
tasks such as low-level data manipulation, performance optimization, and implementing
algorithms that require direct access to bits.

21
Shift Operators: In Java, shift operators are the special type of operators that work on the
bits of the data. These operators are used to shift the bits of the numbers from left to right
or right to left depending on the type of shift operator used.

22
Ternary Operators: The ternary operator in Java is a shorthand for the ‘if-else’ statement
and is also known as the conditional operator. It takes three operands and evaluates a
boolean expression, returning one of two values based on the evaluation.
Syntax:
condition ? expression1 : expression2;
condition: A boolean expression that evaluates to true or false.
expression1: The value returned if the condition is true.
expression2: The value returned if the condition is false.

24
• If- statement
The Java if statement is used to test the
condition. It checks the boolean condition:
true or false.
An ‘if’ statement allows you to run a block of
code only if a specified condition is true.
It's a fundamental part of programming that
helps you control the flow of your code.
if(condition)
{
//code to be executed
}

25
• If-else statement
The Java if-else statement is used to execute one
block of code if a condition is true and another block
of code if that condition is false.
It helps you make decisions in your code based on
certain conditions.
if(condition)
{
//code if condition is true
}
else
{
//code if condition is false
}
[Note: We can also use ternary operator (? :) to perform
the task of if...else statement. It is a shorthand way to
check the condition. If the condition is true, the result
of ? is returned. But, if the condition is false, the result of
: is returned.]

26
• If-else-if statement
The if-else-if ladder statement executes one condition
from multiple statements.
if(condition1){
//code to be executed if condition1 is true
}else if(condition2){
}
else if(condition3){
}
...
else{
//code to be executed if all the conditions are
false
}

28
• Nested if statement
Nested if statements are if statements placed inside
another if statement. Here, the inner if block
condition executes only when outer if block condition
is true.
if(condition)
{
if(condition)
{
}
}

29
• Switch statement
A switch statement is a control structure used in many
programming languages to execute different blocks of
code based on the value of a variable or expression.
It is often cleaner and more efficient than using multiple
if-elseif-else statements when you have a variable that
can take on a number of discrete values.
switch(expression){
case value1:
//code to be executed;
break; //optional
case value2:
//code to be executed;
break; //optional
......
default:
code to be executed if all cases are not
matched;
}

33
public class ForLoopExample
{
public static void main(String[] args)
{
for (int i = 0; i < 5; i++)
{
System.out.println("Iteration: " +
i);
}
}
}

39
public class WhileExample
{
{
int i=1;
while(i<=10)
{
System.out.println(i);
i++;
}
}
}

41
public class DoWhileExample
{
{
int i=1;
do
{
System.out.println(i);
i++;
}while(i<=10);
}
}

46
public class ContinueInForLoop
{
{
for (int i = 1; i <= 10; i++)
{
if (i % 2 == 0) { // Skip even
numbers
continue; // Skip to the next
iteration
}
System.out.println(i); // Print odd
numbers
}
}
}
Output
1
3
5
7
9

UNIT – 2 Features of java- (Shilpa R).pptx

More Related Content

Similar to UNIT – 2 Features of java- (Shilpa R).pptx

More from shilpar780389

Recently uploaded

UNIT – 2 Features of java- (Shilpa R).pptx