Corporate Training Study Material
Naming Conventions & Control Flow Statements in Java
🔹 Session Objectives
By the end of this
session, participants will:
✔ Understand best
practices for naming identifiers in Java.
✔ Learn about if-else
statements and how to use them for decision-making.
✔ Implement switch-case
statements for multi-way branching.
✔ Explore looping
constructs (for, while, do-while) to handle repetitive tasks.
📌 1. Java Naming
Conventions
Naming conventions in
Java help make the code readable, maintainable, and consistent. The Java
community follows these widely accepted standards.
🔹 Best Practices for
Naming Identifiers
1️⃣ Class Names
- Use
PascalCase (CamelCase with first letter capitalized).
- Should
be a noun (representing an object or concept).
- Example:
class EmployeeDetails { }
class BankAccount { }
2️⃣ Variable Names
- Use
camelCase (first letter lowercase, following words capitalized).
- Should
be meaningful and descriptive.
- Example:
int employeeId;
double accountBalance;
3️⃣ Method Names
- Use
camelCase, starting with a verb
(action).
- Example:
void calculateSalary() { }
int getAge() { return
age; }
4️⃣ Constant
Variables
- Use
UPPER_CASE with underscores.
- Example:
final int MAX_AGE = 60;
final double INTEREST_RATE
= 4.5;
5️⃣ Package Names
- Use
lowercase words, separated by dots (.).
- Example:
package com.companyname.projectname;
📌 2. Control Flow
Statements
Control flow statements
help define the logic flow of the program. They determine which parts
of code execute and how many times.
🔹 1️⃣ Decision-Making
Statements
Used to execute specific
blocks of code based on conditions.
1️⃣ If-Else Statement
Syntax:
if (condition) {
// Code executes if condition is true
} else {
// Code executes if condition is false
}
Example:
public class IfElseExample {
public static void main(String[] args) {
int age = 18;
if (age >= 18) {
System.out.println("You are
eligible to vote.");
} else {
System.out.println("You are
not eligible to vote.");
}
}
}
Output:
You are eligible to vote.
2️⃣ If-Else If Ladder
Used when there are multiple
conditions to check.
Example:
public class IfElseIfExample {
public static void main(String[] args) {
int marks = 85;
if (marks >= 90) {
System.out.println("Grade:
A");
} else if (marks >= 75) {
System.out.println("Grade:
B");
} else {
System.out.println("Grade:
C");
}
}
}
Output:
Grade: B
🔹 2️⃣ Switch-Case
Statement
Used when multiple
conditions need to be checked on the same variable.
Syntax:
switch (expression) {
case value1:
// Code block
break;
case value2:
//
Code block
break;
default:
// Default block (if no cases match)
}
Example:
public class SwitchExample {
public static void main(String[] args) {
int day = 3;
switch (day) {
case 1:
System.out.println("Monday");
break;
case 2:
System.out.println("Tuesday");
break;
case 3:
System.out.println("Wednesday");
break;
default:
System.out.println("Invalid
Day");
}
}
}
Output:
Wednesday
🔹 3️⃣ Looping
Constructs
Loops allow us to execute
a block of code multiple times.
1️⃣ For Loop
Used when the number of
iterations is known.
Syntax:
for(initialization; condition; increment/decrement) {
// Code to execute
}
Example:
public class ForLoopExample {
public static void main(String[] args) {
for (int i = 1; i <= 5; i++) {
System.out.println("Iteration:
" + i);
}
}
}
Output:
Iteration: 1
Iteration: 2
Iteration: 3
Iteration: 4
Iteration: 5
2️⃣ While Loop
Used when the number of
iterations is unknown.
Syntax:
while(condition) {
// Code to execute
}
Example:
public class WhileLoopExample {
public static void main(String[] args) {
int count = 1;
while (count <= 5) {
System.out.println("Count:
" + count);
count++;
}
}
}
Output:
Count: 1
Count: 2
Count: 3
Count: 4
Count: 5
3️⃣ Do-While Loop
Ensures the loop executes
at least once.
Syntax:
do {
// Code to execute
} while (condition);
Example:
public class DoWhileExample {
public static void main(String[] args) {
int num = 1;
do {
System.out.println("Number:
" + num);
num++;
} while (num <= 5);
}
}
Output:
Number: 1
Number: 2
Number: 3
Number: 4
Number: 5
📌 Summary
|
Concept |
Key Points |
|
Naming Conventions |
Follow best practices
for readability and maintainability. |
|
If-Else Statement |
Used for conditional
execution. |
|
Switch-Case Statement |
Used for multi-way
branching. |
|
For Loop |
Executes for a known
number of times. |
|
While Loop |
Executes as long as the
condition is true. |
|
Do-While Loop |
Executes at least once
before checking the condition. |
✅ Practice Assignments
1️⃣ Write a program to check
if a number is positive, negative, or zero using if-else.
2️⃣ Implement a switch-case
program that takes a month number and prints the month name.
3️⃣ Write a for loop
to print the first 10 natural numbers.
4️⃣ Use a while loop
to find the sum of digits of a given number.
5️⃣ Create a do-while
loop to print numbers from 10 to 1.
1.
Naming Conventions
2.
Decision-Making Statements (If-Else,
Switch-Case)
3.
Looping Constructs (For, While,
Do-While)
🔹 Section 1: Naming
Conventions (5 Assignments)
Assignment 1: Follow
Proper Naming Conventions
🔹 Task: Create a Java class
named EmployeeDetails with variables employeeId, employeeName, and employeeSalary.
🔹 Code:
class EmployeeDetails {
int employeeId;
String employeeName;
double employeeSalary;
void displayEmployeeInfo() {
System.out.println("Employee ID:
" + employeeId);
System.out.println("Employee Name:
" + employeeName);
System.out.println("Employee
Salary: " + employeeSalary);
}
}
public class NamingConventionExample
{
public static void main(String[] args) {
EmployeeDetails emp = new EmployeeDetails();
emp.employeeId = 101;
emp.employeeName = "John Doe";
emp.employeeSalary = 50000;
emp.displayEmployeeInfo();
}
}
🔹 Output:
Employee ID: 101
Employee Name: John Doe
Employee Salary: 50000.0
Assignment 2: PascalCase
for Class Name
🔹 Task: Create a class BankAccount
with methods depositAmount and withdrawAmount.
🔹 Code:
class BankAccount {
double balance = 0;
void depositAmount(double amount) {
balance += amount;
}
void withdrawAmount(double amount) {
if (amount <= balance) {
balance -= amount;
} else {
System.out.println("Insufficient
Balance");
}
}
}
public class BankTransaction
{
public static void main(String[] args) {
BankAccount account = new BankAccount();
account.depositAmount(1000);
account.withdrawAmount(500);
System.out.println("Remaining
Balance: " + account.balance);
}
}
🔹 Output:
Remaining Balance: 500.0
Assignment 3: Use of
Constants in Java
🔹 Task: Define a constant PI
and use it to calculate the area of a circle.
🔹 Code:
class Circle {
final double PI = 3.14159;
double calculateArea(double radius) {
return PI * radius * radius;
}
}
public class ConstantExample
{
public static void main(String[] args) {
Circle circle = new Circle();
System.out.println("Area: " +
circle.calculateArea(5));
}
}
🔹 Output:
Area: 78.53975
Assignment 4: CamelCase
for Method Names
🔹 Task: Create a class StudentMarks
with a method calculatePercentage().
🔹 Code:
class StudentMarks {
double calculatePercentage(int marks, int
totalMarks) {
return (marks * 100.0) / totalMarks;
}
}
public class StudentTest
{
public static void main(String[] args) {
StudentMarks student = new StudentMarks();
System.out.println("Percentage:
" + student.calculatePercentage(450, 500) + "%");
}
}
🔹 Output:
Percentage: 90.0%
Assignment 5: Package
Naming Conventions
🔹 Task: Create a package named com.company.hr
and add a class Employee.
🔹 Code:
package com.company.hr;
class Employee {
String name;
Employee(String name) {
this.name = name;
}
void display() {
System.out.println("Employee:
" + name);
}
}
🔹 Section 2:
Decision-Making Statements (5 Assignments)
Assignment 6: Check
Positive, Negative, or Zero
🔹 Task: Use if-else to check if
a number is positive, negative, or zero.
🔹 Code:
public class NumberCheck {
public static void main(String[] args) {
int num = -5;
if (num > 0)
System.out.println("Positive
Number");
else if (num < 0)
System.out.println("Negative
Number");
else
System.out.println("Zero");
}
}
🔹 Output:
Negative Number
Assignment 7: Check Leap
Year
🔹 Task: Use if-else to check if
a year is a leap year.
🔹 Code:
public class LeapYearCheck {
public static void main(String[] args) {
int year = 2024;
if (year % 4 == 0 && (year % 100
!= 0 || year % 400 == 0)) {
System.out.println(year + " is
a Leap Year");
} else {
System.out.println(year + " is
not a Leap Year");
}
}
}
🔹 Output:
2024 is a Leap Year
Assignment 8: Find
Maximum of Three Numbers
🔹 Task: Use if-else to find the
largest of three numbers.
🔹 Code:
public class MaxNumber {
public static void main(String[] args) {
int a = 10, b = 20, c = 15;
if (a > b && a > c)
System.out.println(a + " is
the largest");
else if (b > c)
System.out.println(b + " is
the largest");
else
System.out.println(c + " is
the largest");
}
}
🔹 Output:
20 is the largest
Assignment 9: Switch Case
for Days of the Week
🔹 Task: Use switch-case to
print the day of the week.
🔹 Code:
public class WeekDay {
public static void main(String[] args) {
int day = 3;
switch (day) {
case 1: System.out.println("Monday");
break;
case 2: System.out.println("Tuesday");
break;
case 3: System.out.println("Wednesday");
break;
default: System.out.println("Invalid
day");
}
}
}
🔹 Output:
Wednesday
Assignment 10: Switch
Case for Vowel Check
🔹 Task: Check if a character is
a vowel using switch-case.
🔹 Code:
public class VowelCheck {
public static void main(String[] args) {
char ch = 'e';
switch (ch) {
case 'a': case 'e': case 'i': case 'o':
case 'u':
System.out.println("Vowel");
break;
default:
System.out.println("Consonant");
}
}
}
🔹 Output:
Vowel
🔹 Section 3: Looping
Statements (5 Assignments)
🔹 Assignment 11: Print Numbers from 1 to 10 using for Loop
🔹 Task: Write a Java program
that prints numbers from 1 to 10 using a for loop.
🔹 Code:
public class ForLoopExample {
public static void main(String[] args) {
for (int i = 1; i <= 10; i++) {
System.out.print(i + " ");
}
}
}
🔹 Output:
1 2 3 4 5 6 7 8 9 10
🔹 Assignment 12: Find Sum
of Digits of a Number using while Loop
🔹 Task: Write a Java program to
find the sum of digits of a given number using a while loop.
🔹 Code:
import java.util.Scanner;
public class SumOfDigits {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter a number:
");
int number = scanner.nextInt();
int sum = 0;
while (number > 0) {
sum += number % 10;
number /= 10;
}
System.out.println("Sum of digits: " + sum);
scanner.close();
}
}
🔹 Input:
Enter a number: 1234
🔹 Output:
Sum of digits: 10
(Explanation: 1 + 2 + 3 +
4 = 10)
🔹 Assignment 13: Reverse a
Number using while Loop
🔹 Task: Write a Java program to
reverse a given number using a while loop.
🔹 Code:
import java.util.Scanner;
public class ReverseNumber {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter a number:
");
int number = scanner.nextInt();
int reverse = 0;
while (number > 0) {
int digit = number % 10;
reverse = reverse * 10 + digit;
number /= 10;
}
System.out.println("Reversed number: " + reverse);
scanner.close();
}
}
🔹 Input:
Enter a number: 1234
🔹 Output:
Reversed number: 4321
🔹 Assignment 14: Print
Fibonacci Series using for Loop
🔹 Task: Write a Java program to
print the Fibonacci series up to n terms using a for loop.
🔹 Code:
import java.util.Scanner;
public class FibonacciSeries {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
System.out.print("Enter the number
of terms: ");
int n = scanner.nextInt();
int first = 0, second = 1;
System.out.print("Fibonacci Series: " + first + " " + second + " ");
for (int i = 3; i <= n; i++) {
int next = first + second;
System.out.print(next + "
");
first = second;
second = next;
}
scanner.close();
}
}
🔹 Input:
Enter the number of terms: 7
🔹 Output:
Fibonacci Series: 0 1 1 2 3 5 8
🔹 Assignment 15: Print
Numbers from 10 to 1 using do-while Loop
🔹 Task: Write a Java program to
print numbers from 10 to 1 using a do-while loop.
🔹 Code:
public class DoWhileExample {
public static void main(String[] args) {
int i = 10;
do {
System.out.print(i + " ");
i--;
} while (i >= 1);
}
}
🔹 Output:
10 9 8 7 6 5 4 3 2 1
