Control Structures

Control structures in Java are used to control the flow of execution in a program. They allow you to make decisions, repeat actions, and create structured, organized code. Java provides three main types of control structures: conditional statements, loops, and branching.

1. Conditional Statements:

Conditional statements help your program make decisions based on conditions.

• if Statement:

    if (condition) {
        // Code to execute if condition is true
    }
  

• if-else Statement:

    if (condition) {
        // Code to execute if condition is true
    } else {
        // Code to execute if condition is false
    }
  

• else-if Ladder:

    if (condition1) {
        // Code to execute if condition1 is true
    } else if (condition2) {
        // Code to execute if condition2 is true
    } else {
        // Code to execute if none of the conditions is true
    }
  

• switch Statement:

    switch (expression) {
        case value1:
            // Code for case value1
            break;
        case value2:
            // Code for case value2
            break;
        // ...
        default:
            // Code for default case
    }
  

2. Loops:

Loops help you repeat a block of code multiple times.

• while Loop:

    while (condition) {
        // Code to repeat as long as condition is true
    }
  

• do-while Loop:

    do {
        // Code to execute at least once, then repeat while condition is true
    } while (condition);
  

• for Loop:

    for (initialization; condition; increment/decrement) {
        // Code to repeat as long as condition is true
    }
  

• enhanced for (foreach) Loop:

    for (data_type variable : array/collection) {
        // Code to iterate through each element of the array/collection
    }
  

3. Branching:

Branching allows you to jump to specific parts of your code based on conditions.

• break Statement: Used to exit a loop or switch statement prematurely.

• continue Statement: Used to skip the rest of the loop's current iteration and move to the next iteration.

• return Statement: Used to exit a method and optionally return a value.

Example:

Here's an example that combines these control structures to create a simple program that prints even and odd numbers between 1 and 10:

public class ControlStructuresExample {
    public static void main(String[] args) {
        for (int i = 1; i <= 10; i++) {
            if (i % 2 == 0) {
                System.out.println(i + " is even");
            } else {
                System.out.println(i + " is odd");
            }
        }
    }
}

Control structures enable you to create dynamic, responsive, and efficient programs by guiding the flow of execution based on conditions and loops.