Chapter 4: Control Flow: Conditional Statements and Loops

Introduction:

Control flow statements allow you to control the execution of your Java program based on certain conditions and repetitions. In this chapter, we will explore conditional statements (if-else and switch) and loops (while, do-while, and for) to enable more dynamic and flexible program execution.

Conditional Statements:

if-else Statement:

The if-else statement allows your program to make decisions based on a condition. It executes a block of code if the condition is true and another block of code if the condition is false.

Example:

java

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int age = 18;

if (age >= 18) {

    System.out.println("You are eligible to vote!");

} else {

    System.out.println("You are not eligible to vote yet.");

}

switch Statement:

The switch statement provides a way to execute different code blocks based on the value of a variable or expression. It simplifies multiple if-else conditions when you have many possible cases.

Example:

java

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int dayOfWeek = 1;

switch (dayOfWeek) {

    case 1:

        System.out.println("Today is Monday.");

        break;

    case 2:

        System.out.println("Today is Tuesday.");

        break;

    // Add more cases for the remaining days

    default:

        System.out.println("Invalid day.");

        break;

}

Loops:

while Loop:

The while loop repeatedly executes a block of code as long as a specified condition is true. It is suitable when you don't know the exact number of iterations in advance.

Example:

java

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int count = 1;

while (count <= 5) {

    System.out.println("Count: " + count);

    count++;

}

do-while Loop:

The do-while loop is similar to the while loop but guarantees that the block of code executes at least once, even if the condition is initially false.

Example:

java

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int count = 1;

do {

    System.out.println("Count: " + count);

    count++;

} while (count <= 5);

for Loop:

The for loop provides a concise way to iterate a specific number of times. It consists of an initialization, a condition, and an increment/decrement expression.

Example:

java

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for (int i = 1; i <= 5; i++) {

    System.out.println("Count: " + i);

}

Loop Control Statements:

break Statement:

The break statement is used to terminate a loop prematurely. It breaks out of the loop and continues with the next statement after the loop.

Example:

java

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for (int i = 1; i <= 10; i++) {

    if (i == 5) {

        break;

    }

    System.out.println("Count: " + i);

}

continue Statement:

The continue statement is used to skip the current iteration of a loop and move to the next iteration.

Example:

java

_____________________________________________

for (int i = 1; i <= 10; i++) {

    if (i % 2 == 0) {

        continue;

    }

    System.out.println("Odd Number: " + i);

}

Conclusion:

In this chapter, we covered conditional statements (if-else and switch) and loops (while, do-while, and for). These control flow statements allow you to make decisions and repeat code based on certain conditions. By mastering these concepts, you can create more dynamic and flexible programs. In the following chapters, we will explore more advanced topics and build upon the control flow concepts learned here.

Note: Make sure to include additional chapters and topics to cover all the essential aspects of Java programming in your book. The provided content is a sample for Chapter 4 only.