@rbxts/jsnatives

toFixed

Formats a number using fixed-point notation.

Signature

function toFixed(value: number, digits?: number): string

Description

The Number.toFixed() method formats a number using fixed-point notation, returning a string representation of the number that does not use exponential notation and has exactly the specified number of digits after the decimal point.

Parameters

value: The number to format.
digits (optional): The number of digits to appear after the decimal point. Must be in the range 0-20, inclusive. Default is 0.

Return value

A string representing the given number using fixed-point notation.

Examples

Basic Usage

// Simple fixed-point formatting
Number.toFixed(123.456, 2);        // "123.46" (rounded)
Number.toFixed(123.456, 0);        // "123" (no decimal part)
Number.toFixed(123.456, 4);        // "123.4560" (padded with zeros)

// Rounding behavior
Number.toFixed(0.125, 2);          // "0.13" (rounded up)
Number.toFixed(0.124, 2);          // "0.12" (rounded down)
Number.toFixed(0.5, 0);            // "1" (rounded up)
Number.toFixed(0.4, 0);            // "0" (rounded down)

// Very small numbers become zero
Number.toFixed(0.0000001, 2);      // "0.00"

// Large numbers maintain their integer part
Number.toFixed(1234567.89, 2);     // "1234567.89"

Formatting Currency

// Format as currency
function formatCurrency(amount: number, currency = "$", decimals = 2): string {
  return currency + Number.toFixed(amount, decimals);
}

// Usage
formatCurrency(123.456);             // "$123.46"
formatCurrency(1234.56, "€", 2);     // "€1234.56"
formatCurrency(99, "£");             // "£99.00"

Percentage Formatting

// Format a decimal as percentage
function formatPercentage(decimal: number, decimals = 1): string {
  return Number.toFixed(decimal * 100, decimals) + "%";
}

// Usage
formatPercentage(0.1234);           // "12.3%"
formatPercentage(0.5, 0);           // "50%"
formatPercentage(1.75, 2);          // "175.00%"