Bagaimana untuk Menukar Nombor Terapung kepada Nombor Bulat dalam JavaScript?

How to Convert a Float Number to a Whole Number in JavaScript

To convert a float number to a whole number, you can use JavaScript's built-in Math object. The Math object provides several methods for handling mathematical operations, including rounding and truncation.

Approaches:

1. Truncation:
Truncation removes the decimal part of the number. To truncate a float number, use Math.floor(). This method rounds down to the nearest integer less than or equal to the original number.

2. Rounding:
Rounding calculates the nearest integer to the original number. To round a float number, use Math.round(). This method rounds to the nearest integer, away from zero.

3. Ceiling:
Ceiling rounds up to the nearest integer greater than or equal to the original number. To ceiling a float number, use Math.ceil().

Examples:

<code class="javascript">var floatNum = 5.4;

// Truncation
var truncatedNum = Math.floor(floatNum); // Result: 5

// Rounding
var roundedNum = Math.round(floatNum); // Result: 5

// Ceiling
var ceilingNum = Math.ceil(floatNum); // Result: 6</code>

Additional Options:

• Math.trunc() was introduced in ECMAScript 6 and truncates the number to the nearest integer towards zero.
• Bitwise operations, such as ~~value or value | 0, can also be used to truncate a number.
• Subtracting the modulo value from the original number (value - value % 1) can also result in integer conversion.

Performance:

Bitwise operations are generally faster than using Math methods. However, parseInt() is the fastest conversion method for integers within the safe integer range.

Reference:

[Math object](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math)

Atas ialah kandungan terperinci Bagaimana untuk Menukar Nombor Terapung kepada Nombor Bulat dalam JavaScript?. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!