Loops and Iterators

Loops allow repeating a block of code while a condition is met or to traverse data sets.

for Loop

Used when you know exactly how many times you want to repeat something.

for (let i = 0; i < 5; i++) {
    console.log("Number: " + i);
}

while Loop

Repeats while the condition is true. Ideal if you don’t know how many iterations it will take.

let counter = 0;
while (counter < 5) {
    console.log(counter);
    counter++;
}

do...while Loop

Similar to while, but guarantees the code executes at least once, since the condition is evaluated at the end.

let i = 1;
do {
    console.log(i);
    i++;
} while (i <= 5);

for...in Loop

Special for traversing the properties of an object.

const person = { name: "Facu", age: 30 };
for (let key in person) {
    console.log(`${key}: ${person[key]}`);
}

Loop Control

• break: Cuts the loop immediately.
• continue: Jumps to the next iteration ignoring what remains of the current one.