0.4 Loops & Jump Statements (`break`, `continue`)

Loops allow you to repeat a block of code multiple times efficiently without writing repetitive code manually.

1. The Anatomy of a `for` Loop

A standard for loop consists of three parts separated by semicolons:

//  (1) Initialization ; (2) Condition ; (3) Increment/Update
for (let i = 0; i < 5; i++) {
    console.log("Iteration number:", i);
}

Initialization: let i = 0 sets up a counter variable.
Condition: i < 5 checked before each loop iteration.
Increment: i++ increases i by 1 after each loop body finishes.

2. `while` and `do...while` Loops

Use a while loop when you don't know in advance how many times to repeat:

let energy = 100;
while (energy > 0) {
    console.log("Running... energy left:", energy);
    energy -= 25; // Decrement energy towards 0
}

3. Controlling Loop Flow: `break` vs `continue`

break: Immediately halts and exits the entire loop.
continue: Skips the rest of the current iteration and jumps straight to the next cycle.

for (let i = 1; i <= 5; i++) {
    if (i === 3) continue; // Skip number 3
    if (i === 5) break;    // Stop loop at 5
    console.log("Number:", i); // Output: 1, 2, 4
}

📌 KEY POINTS TO REMEMBER

`break` vs `continue`: break destroys the loop immediately. continue skips current step and moves to next step.
Preventing Infinite Loops: Always ensure the condition in a while loop will eventually become false (e.g. updating the counter inside the loop body).
Zero-Indexing: Loops commonly start counting from 0 (e.g., let i = 0).

⚡ Interactive Visual: Loop Stepper & Jump Control

Run interactive loop simulations with break/continue:

Click a loop button above.