3.4. Looping Statements

Used to repeat a block of code multiple times.

Looping statements in programming allow specific sections of code to repeat execution multiple times based on conditions. This is essential for automating repetitive tasks without rewriting code.

Consider a bakery that needs to make 100 cupcakes. Instead of manually preparing each cupcake one by one and writing down instructions each time, the bakery can use a recipe template that can be followed repeatedly. Each time they follow the template, they are effectively 'looping' through the same process.

✅ A. for Loop Best when the number of iterations is known.

for (int i = 1; i <= 5; i++) {
    System.out.println("Hello " + i);
}

The 'for loop' is designed for situations where you know exactly how many times you want to repeat a code block. In the example, the for loop initializes an integer i at 1, checks if i is less than or equal to 5, and then increments i by 1 after each iteration. This ensures that the loop runs exactly 5 times, printing 'Hello 1', 'Hello 2', etc.

Imagine a teacher who needs to give a standard greeting to each student as they enter the classroom, and there are exactly 5 students. The teacher can simply follow a script that says, 'Hello, student X', where X is the student number. The for loop functions similarly, repeating the script for each student in the known group.

✅ B. while Loop Used when the number of iterations is unknown.

int i = 1;
while (i <= 3) {
    System.out.println("Number: " + i);
    i++;
}

The 'while loop' continues to execute as long as a specified condition remains true. In this example, the loop will keep printing 'Number: i' as long as i is less than or equal to 3. The condition is checked before the loop body is executed, ensuring that if the condition is false from the start, the loop never executes.

Think of a runner who keeps jogging as long as they feel good. They don’t know exactly how far they'll run. They just keep going until they no longer feel like running. This is like the while loop, which will keep executing as long as the condition holds.

✅ C. do-while Loop Same as while, but the block is executed at least once.

int i = 1;
do {
    System.out.println("Value: " + i);
    i++;
} while (i <= 3);

The 'do-while loop' is similar to the 'while loop', but it guarantees that the code inside the loop is executed at least once. In the provided code, 'Value: i' will be printed regardless of the condition because the check occurs after the code block has been executed.

Imagine a fan that has to spin at least once when you turn it on, regardless of whether you later decide to adjust the speed or turn it off. Even if you quickly change your mind, the fan still spins once. The do-while loop operates in the same way, executing the block of code first before checking if it should continue.

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