Explain the purpose of the %= operator in JavaScript.

In JavaScript, the `%=` operator is the assignment operator combined with the modulo operation. It is used to update the value of a variable by taking the remainder of the division of its current value by another value and assigning the result back to the variable.

Here's an example:

let x = 10;

let y = 3;

x %= y;

console.log(x);  // Outputs: 1

In this example:

- `x` initially has a value of `10`.

- `x %= y;` is equivalent to `x = x % y;`, which means "take the current value of `x`, divide it by the value of `y`, and assign the remainder back to `x`."

- After the operation, the value of `x` becomes `1` because `10 % 3` equals `1`.

The `%=` operator is a shorthand way of performing the modulo operation along with assignment. It is commonly used when you want to update a variable based on the remainder of a division operation.

This operator is not limited to integers; it can be used with floating-point numbers as well. However, keep in mind that floating-point operations may involve precision issues due to the nature of floating-point arithmetic.