@alwatr/math

@alwatr/math

Simple useful Math library written in tiny TypeScript module.

API

isNumber(value: unknown): boolean

Why is this needed?

console.log(typeof '123'); //=> 'string'
console.log(+[]); //=> 0
console.log(+''); //=> 0
console.log(+'   '); //=> 0
console.log(typeof NaN); //=> 'number'
console.log(typeof Infinity); //=> 'number'

True

import { isNumber } from 'https://esm.run/@alwatr/math';

isNumber(5e3);               // true
isNumber(0xff);              // true
isNumber(-1.1);              // true
isNumber(0);                 // true
isNumber(1);                 // true
isNumber(1.1);               // true
isNumber(10);                // true
isNumber(10.10);             // true
isNumber(100);               // true
isNumber('-1.1');            // true
isNumber('0');               // true
isNumber('012');             // true
isNumber('0xff');            // true
isNumber('1');               // true
isNumber('1.1');             // true
isNumber('10');              // true
isNumber('10.10');           // true
isNumber('100');             // true
isNumber('5e3');             // true
isNumber(parseInt('012'));   // true
isNumber(parseFloat('012')); // true

False

import { isNumber } from 'https://esm.run/@alwatr/math';

isNumber(Infinity);          // false
isNumber(NaN);               // false
isNumber(null);              // false
isNumber(undefined);         // false
isNumber('');                // false
isNumber('   ');             // false
isNumber('foo');             // false
isNumber([1]);               // false
isNumber([]);                // false
isNumber(function () {});    // false
isNumber({});                // false

transformToRange(x: number, options}): number

Transform a number from one range to another.

Options:

{
  /**
   * The input range [min, max].
   *
   */
  in: [number, number];

  /**
   * The output (request) range [min, max].
   */
  out: [number, number];

  /**
   * If true, the output will be bounded to the output range (between min and max).
   *
   * In default behavior when x (input number) does not between input min~max range,
   * the output value will be out of output min~max range.
   *
   */
  bound?: boolean;
}

Example

transformToRange(5, {in: [0, 10], out: [0, 100]}); // => 50

Make percentage of any value

transformToRange(2000, {in: [0, 5000], out: [0, 100]}); // => 40

Calculate progress-bar with

const progressOuterWith = 400; //px
const gap = 5; //px (the visual gap between progressBar and component outer).
const currentProgress = 30; //%

const progressBarWith = transformToRange(currentProgress, {
  in: [0, 100],
  out: [componentPadding, progressOuterWith - componentPadding],
  bound: true,
});

this.progressBar.style.width = `${progressBarWith}px`;

Generate Random

value

Returns a float random number between 0 and 1 (1 Not included).

console.log(random.value); // 0.7124123

random.integer(min: number, max: number): number

Generate a random integer between min and max.

console.log(random.integer(1, 10)); // somewhere between 1 and 10

random.float(min: number, max: number): number

Generate a random float between min and max.

console.log(random.float(1, 10)); // somewhere between 1 and 10

step(min: number, max: number, step: number): number

Generate a random integer between min and max with a step.

console.log(random.step(6, 10, 2)); // 6 or 8 or 10

shuffle(array: any[]): any[]

Shuffle an array.

const array = [1, 2, 3, 4, 5];
random.shuffle(array);
console.log(array); // [2, 4, 3, 1, 5]