While Loop

A while loop is different from the for loop. A for loop allows us to iterate over a specific range, whereas a while loop allows us to keep iterating as long as a certain condition is met.

To use a while loop write:

while (condition) {
	code;
}

The code will execute only if the condition is true.

There are many use cases where a while loop is more suitable than a for loop — especially when the number of iterations is not known in advance.

For example consider this problem:

Find the smallest power of 2 that is greater than a given number.

To solve it we will use a while loop that will repeatedly multiply the current power of 2 by 2 until it becomes greater than the given number:

let number = 27;
let power_of_two = 1;

while (power_of_two <= number) {
    power_of_two *= 2;
}

console.log(power_of_two);