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Convert to Decimal

convertToDecimal​

The convertToDecimal function rounds a number to a specified number of decimal places and returns it as either a number or string, based on the provided options.

Function Signature​

convertToDecimal<T extends boolean | undefined = false>(
    input: Numeric, options?: DecimalOptions<T>
): ConvertedDecimal<T>;

Parameters​

  • input: A number or a numeric string that needs to be rounded.
  • options (optional): Configuration object to customize the rounding behavior.
    • decimalPlaces (optional): The number of decimal places to round to. Defaults to 2.
    • isString (optional): If set to true, the result will be returned as a string. Defaults to false, which returns the result as a number.

Return Value​

  • Returns the input number rounded to the specified decimal places.
  • The type of the return value depends on the isString option:
    • If isString is false (default), the result is returned as a number.
    • If isString is true, the result is returned as a string.

Example Usage​

Default (Returns Number)​

import { convertToDecimal } from 'nhb-toolbox';

console.log(convertToDecimal(3.14159));         // 3.14
console.log(convertToDecimal(3.14159, { decimalPlaces: 3 }));  // 3.142

With String Output​

import { convertToDecimal } from 'nhb-toolbox';

console.log(convertToDecimal(3.14159, { isString: true }));  // "3.14"
console.log(convertToDecimal(3.14159, { decimalPlaces: 3, isString: true }));  // "3.142"

Type: Numeric​

A union type representing either a number or a numeric string (e.g., "42.5"):

type Numeric = number | `${number}`;

Notes​

  • The function rounds the number based on the specified decimalPlaces, applying standard rounding rules.
  • The default behavior is to return the result as a number, but it can be easily configured to return a string.
  • If the input is already a numeric string, it will be automatically converted to a number for rounding.
  • roundNumber: Use when you need rounding to specific decimal places (including negative places for whole number rounding) without string output options.
  • roundToNearest: Use when you need to round to arbitrary intervals (like multiples of 5, 10, etc.) rather than decimal places.
  • For comparison see here

Aliases​

convertToDecimal can also be imported using the alias:

  • convertToFixed

Conclusion​

The convertToDecimal function is ideal for scenarios where you need to round numbers to a specific precision and control whether the result is returned as a number or a string.