<script src="https://cdnjs.cloudflare.com/ajax/libs/react/17.0.2/umd/react.development.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/17.0.2/umd/react-dom.development.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.26.0/babel.min.js"></script>
<script type="text/babel">
const { useState, useEffect } = React;
const array = [1, 2, 3, 4, 5, 3, 6, 7];
const findFirstOccurrence = () => {
const startIndex = array.indexOf(searchElement, specificIndex);
<div className='container'>
<h3>React Js indexof() Method Example</h3>
<p>Array: <span className='array'>{array.join(', ')}</span></p>
<p>Specific Index: <span className='specific-index'>{specificIndex}</span></p>
<p>Search Element: <span className='search-element'>{searchElement}</span></p>
<p>First Occurrence Index: <span className='first-occurrence-index'>{findFirstOccurrence()}</span></p>
ReactDOM.render(<App />, document.getElementById('app'));
box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.12), 0 2px 4px 0 rgba(0, 0, 0, 0.24);