JAVA Basics: continuation from ppt 1

1. Unit 2: Loop Statements in
Java
for,
while,
do-while

2. 1. For Loop
• For loop is used when the number of iterations is known.

4. 2. While Loop
• Used when the number of iterations is not known in advance.

7. 2. Do-While Loop
• Executes the loop at least once, then checks the condition.

9. Jump statements in Java
• Jump statements alter the normal flow of control in a program. They are
used to break, skip, or jump out of loops or blocks based on conditions.
1. break Statement
• Function: Terminates the loop or switch statement and transfers control to
the next statement after the loop or switch.
📌 Use Cases:
• To exit a loop early.
• To exit a switch case.

13. 2. continue statement
• Function: Skips the current iteration of the loop and jumps to the next
iteration.
📌 Use Case:
• To skip specific values or steps within a loop.
🔹 Example: Printing odd numbers by skipping even numbers

15. Example: Skip number 3

16. Example: Print even numbers from 1 to 10

17. Arrays in Java
1. Declaration of Arrays
• Declaring an array means telling Java about the type and structure.
• int[] numbers; // Preferred style
• String names[]; // Also valid
2. Instantiation of Arrays
• Instantiating means creating memory using the new keyword.
• numbers = new int[5]; // Creates an array to store 5 integers

18. 3. Initialization of Arrays
• Initialization means assigning values to array elements.
Example:
numbers = new int[5];
numbers[0] = 10;
numbers[1] = 20;
numbers[2] = 30;
numbers[3] = 40;
numbers[4] = 50;
int[] number = {10, 20, 30, 40, 50};

19. 2. Types of Arrays in Java
(a) Single-Dimensional Array
• It stores a list of elements in a single row:
String[] fruits = {"Apple", "Banana", "Mango"};
for (int i = 0; i < fruits.length; i++) {
System.out.println(fruits[i]);
}

20. Example 1: Declare, Instantiate, and Initialize separately

23. (b) Multidimensional (2D) Array
• A multidimensional array is an array of arrays.
• In Java, the most commonly used multidimensional array is the two-
dimensional (2D) array, which is like a table or matrix.
• Each element is accessed using two indices: one for the row and one
for the column.