Usage of utility classes in Lightning web component:

In this demo, explaining about the usage of utility classes in Lwc. I have created utility class inside the  component folder. Utility class name is "Utilityhelper".

Utility helper is referred in component of JavaScript Like below :

import {add,sub} from './utilityhelper.js';

Complete code Snippet:

shareCode.html

<template>

    <lightning-card title="Usage of Javascript Utility Classes">

    <p> add : {resultFromHelper} </p>

    <p> sub : {substractVal} </p>

</lightning-card>

</template>

Javascript

import { LightningElement } from 'lwc';

import {add,sub} from './utilityhelper.js';

export default class UtilityComponent extends LightningElement {

    resultFromHelper;

    substractVal ;

    constructor(){

        super();

        const result = add(1,9);

        this.resultFromHelper=result;

        this.substractVal=sub();

 }

}

xml

<?xml version="1.0" encoding="UTF-8"?>

<LightningComponentBundle xmlns="http://soap.sforce.com/2006/04/metadata">

    <apiVersion>50.0</apiVersion>

     <isExposed>true</isExposed> 

    <targets>

        <target>lightning__AppPage</target>

        <target>lightning__RecordPage</target>

        <target>lightning__HomePage</target>

    </targets>

</LightningComponentBundle>

utilityhelper

/** helper class */

function add(a,b){

  return a+b;

}

function sub(a,b){

  return 5-3; //Hardcoded 

}

export{add,sub};