# while loop in JavaScript

The `while` loop will run as long as an expression passed to it as a parameter is true. It allows you to perform an arbitrary number of iterations. Here is its syntax:

`while ( while the expression is true ) { executes this code cyclically; at the beginning of each loop, we check the expression in parentheses }`

The loop will end when the expression is no longer true. If it was false initially, then it will never be executed.

Let's use the `while` loop to sequentially display numbers from one to five as an example:

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

And now we will divide the given number by `2` as many times until the result becomes less than `10`:

`let num = 500; while (num > 10) { num = num / 2; } console.log(num); // the result`

Print the numbers from `1` to `100` to the console.

Print the numbers from `11` to `33` to the console.

Given the number `num` with some initial value. Multiply it by `3` as many times until the result of the multiplication is greater than `1000`. What number will come out? Count the number of iterations required for this.

←→
↑
en ru