Question
Answer and Explanation
In JavaScript, toFixed() is a method that belongs to the Number object. It's used to format a number using fixed-point notation. This means it converts a number into a string, rounding it to a specified number of decimal places.
Here's a breakdown of how toFixed() works:
Syntax:
number.toFixed(digits)
Where:
number is the number you want to format.
digits is an integer between 0 and 20 (inclusive), representing the number of digits after the decimal point. If this argument is omitted, it's treated as 0.
Key Features:
1. Rounding: The toFixed() method rounds the number to the specified number of decimal places. It uses standard rounding rules (e.g., 0.5 rounds up).
2. String Output: It always returns a string representation of the number, even if the number of decimal places is zero.
3. Padding with Zeros: If the number has fewer decimal places than specified, it pads the result with zeros to reach the desired length.
4. Range of Digits: The digits argument must be between 0 and 20. If you provide a value outside this range, it will throw a RangeError.
Examples:
let num = 3.14159;
let roundedNum = num.toFixed(2); // Returns "3.14"
let roundedNumZero = num.toFixed(0); // Returns "3"
let paddedNum = num.toFixed(5); // Returns "3.14159"
let anotherNum = 5;
let paddedAnotherNum = anotherNum.toFixed(2); // Returns "5.00"
Use Cases:
toFixed() is commonly used in scenarios where you need to display numbers with a specific number of decimal places, such as:
- Displaying prices or currency values.
- Showing measurements or scientific data.
- Formatting numbers for user interfaces.
Important Note:
Because toFixed() returns a string, you might need to convert it back to a number using parseFloat() or Number() if you need to perform further mathematical operations.
In summary, toFixed() is a useful method for controlling the precision and formatting of numbers in JavaScript, especially when dealing with user-facing data.