JS Loops

JS Loops

Loops allow you to repeat a block of code multiple times. They are commonly used when working with arrays, counters, and dynamic data.

JS Loop for

The for loop runs a block of code a specific number of times.

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

The for loop has three parts: initialization, condition, and increment.

JS Loop while

The while loop runs as long as the condition is true.

let i = 0;

while (i < 5) {
  console.log(i);
  i++;
}

Be careful: if the condition never becomes false, the loop will run forever.

do...while Loop

The do...while loop runs at least once, even if the condition is false.

let n = 0;

do {
  console.log(n);
  n++;
} while (n < 3);

JS Break

The break statement stops a loop immediately.

for (let i = 0; i < 10; i++) {
  if (i === 5) {
    break;
  }
  console.log(i);
}

JS Continue

The continue statement skips the current iteration and continues with the next one.

for (let i = 0; i < 5; i++) {
  if (i === 2) {
    continue;
  }
  console.log(i);
}

JS Control Flow

Control flow statements determine how code is executed. Loops, conditions, break, and continue are all part of JavaScript control flow.

You can also loop through arrays using for...of:

const numbers = [10, 20, 30];

for (const value of numbers) {
  console.log(value);
}

Use for...in when iterating over object properties:

const user = { name: "John", age: 30 };

for (const key in user) {
  console.log(key, user[key]);
}

Next Step

Continue with JS Strings to learn how to work with text in JavaScript.