@alwatr/math

@alwatr/math

Simple useful Math library written in tiny TypeScript module.

API

isNumber(value: unknown): boolean

Check the value is number or can convert to a number, for example string ' 123 ' can be converted to 123.

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

string: (min: number, max?: number): string

Generate a random string with random length.
The string will contain only characters from the characters list.
The length of the string will be between min and max (max included).
If max not specified, the length will be set to min.

console.log(random.string(6)); // something like 'Aab1V2'

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]