Loops and Iterators

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

for Loop

Use it 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 contador = 0;
while (contador < 5) {
    console.log(contador);
    contador++;
}

do...while Loop

Similar to while, but guarantees the code runs 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

Specifically for traversing the properties of an object.

const persona = { nombre: "Facu", edad: 30 };
for (let clave in persona) {
    console.log(`${clave}: ${persona[clave]}`);
}

Loop Control

• break: Exits the loop immediately.
• continue: Skips to the next iteration of the loop, ignoring the rest of the current one.