How do you round a JavaScript number to the nearest whole number?

In JavaScript, you can round a number to the nearest whole number using the built-in Math.round() method. This method rounds a number to the nearest integer. If the decimal part is .5 or greater, it rounds up; otherwise, it rounds down.

Here's how to use Math.round():

Basic Usage

The general syntax is straightforward:

Math.round(number)

Where number is the value you want to round.

Examples:

console.log(Math.round(3.4)); // Output: 3
console.log(Math.round(3.5)); // Output: 4
console.log(Math.round(3.6)); // Output: 4
console.log(Math.round(-3.4)); // Output: -3
console.log(Math.round(-3.5)); // Output: -3
console.log(Math.round(-3.6)); // Output: -4


Handling different scenarios:

It's important to note that Math.round() always rounds to the nearest integer. For more specific rounding behaviors like rounding up (ceiling) or down (floor) independently of decimal value, you can use Math.ceil() and Math.floor() respectively.

Math.ceil(): Rounds the number up to the nearest integer.

console.log(Math.ceil(3.2)); // Output: 4
console.log(Math.ceil(3.7)); // Output: 4
console.log(Math.ceil(-3.2)); // Output: -3
console.log(Math.ceil(-3.7)); // Output: -3


Math.floor(): Rounds the number down to the nearest integer.

console.log(Math.floor(3.2)); // Output: 3
console.log(Math.floor(3.7)); // Output: 3
console.log(Math.floor(-3.2)); // Output: -4
console.log(Math.floor(-3.7)); // Output: -4


In summary, Math.round() is the correct method to use to round a JavaScript number to the nearest whole number. Remember to use Math.ceil() or Math.floor() for specific rounding requirements.

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