input, textarea input.value = "New value" textarea.value = "New text" input.checked = true textarea.innerHTML - do not use, stores only initial HTML, not the current value select, option select.options the collection of <option> els select.value the value of the currently selected <option> select.selectedIndex the index of the currently selected <option> select.options[2].selected = true set a value for a <select> select.selectedIndex = 2 same select.value = 'banana' same multiple options selection <select> allows to select multiple options if it has multiple attribute This attribute is rarely used, though <select id="select" multiple> <option value="blues" selected>Blues</option> <option value="rock" selected>Rock</option> <option value="classic">Classic</option> </select> Get all selected values from multi-select... const selected = Array.from(select.options) .filter(option => option.selected) .map(option => option.value); alert(selected) // blues,rock new Option option = new Option(text, value, defaultSelected, selected) text the text inside the option value the option value defaultSelected if true , then selected HTML-attribute is created selected if true , then the option is selected let option = new Option("Text", "value", true, true) // selected // set both of them let option = new Option("Text", "value") // unselected option.selected // the option selected option.index // number of the option among the others in its <select> option.text // Text content of the option (seen by the visitor). Submit on Enter To submit a form either click on button or push Enter <form onSubmit={e => { e.preventDefault() alert('submitted') }} > <input type="text" placeholder='Press Enter' /> <button>Go</button> </form> Inputs in React Here are uncontrolled React input elements of different types in a form <form action="/api/action_for_inputs_post" method="POST" autoComplete="off" name="myForm" > <fieldset> <legend>Radios</legend> <input type="radio" id="html" name="fav_language" defaultValue="HTML" defaultChecked /> <label htmlFor="html">HTML</label><br /> <input type="radio" id="css" name="fav_language" defaultValue="CSS" /> <label htmlFor="css">CSS</label><br /> <input type="radio" id="javascript" name="fav_language" defaultValue="JavaScript" /> <label htmlFor="javascript">JavaScript</label> </fieldset> <fieldset> <legend>Checkboxes</legend> <input type="checkbox" id="vehicle1" name="vehicles" defaultValue="Bike" defaultChecked /> <label htmlFor="vehicle1"> I have a bike</label><br /> <input type="checkbox" id="vehicle2" name="vehicles" defaultValue="Car" defaultChecked /> <label htmlFor="vehicle2"> I have a car</label><br /> <input type="checkbox" id="vehicle3" name="vehicles" defaultValue="Boat" /> <label htmlFor="vehicle3"> I have a boat</label> </fieldset> <fieldset> <legend>Text inputs</legend> <label htmlFor="fname">First name - readonly:</label><br /> <input type="text" id="fname" name="user" defaultValue="John" readOnly /><br /> <label htmlFor="lname">Last name - disabled:</label><br /> <input type="text" id="lname" name="user" defaultValue="Doe" disabled /><br /> <label htmlFor="age">age:</label><br /> <input type="number" id="age" name="user" defaultValue="35" /> </fieldset> <fieldset> <legend>List input with datalist</legend> <input list="browsers" name="browser" defaultValue="Chrome" /> <datalist id="browsers"> <option defaultValue="Internet Explorer">Internet Explorer</option> <option defaultValue="Firefox">Firefox</option> <option defaultValue="Chrome">Chrome</option> <option defaultValue="Opera">Opera</option> <option defaultValue="Safari">Safari</option> </datalist> </fieldset> <fieldset> <legend>Select</legend> <label htmlFor="cars">Choose a car:</label><br /> <select id="cars" name="cars" size="3" multiple defaultValue={["Volvo", "Fiat"]}> <option>Volvo</option> <option>Saab</option> <option>Fiat</option> <option>Audi</option> </select> </fieldset> <fieldset> <legend>Textarea</legend> <textarea name="message" rows="10" cols="30" defaultValue='The cat was playing in the garden.' /> </fieldset> <fieldset> <legend>Password</legend> <label htmlFor="username">Username:</label><br /> <input type="text" id="username" name="login" defaultValue="login" /><br /> <label htmlFor="pwd">Password:</label><br /> <input type="password" id="pwd" name="pwd" defaultValue="password" /> </fieldset> <fieldset> <legend>Color</legend> <label htmlFor="favcolor">Select your favorite color:</label> <input type="color" id="favcolor" name="favcolor" defaultValue="#ff0000" /> </fieldset> <fieldset> <legend>Date</legend> <label htmlFor="birthday">Birthday:</label> <input type="date" id="birthday" name="birthday" min="2010-01-02" max="2025-12-31" defaultValue="2022-06-06" /> </fieldset> <fieldset> <legend>Datetime-local</legend> <label htmlFor="birthdaytime">Birthday (date and time):</label> <input type="datetime-local" id="birthdaytime" name="birthday time" defaultValue="2022-04-08T14:18" /> </fieldset> <fieldset> <legend>Email</legend> <label htmlFor="email">Enter your email:</label> <input type="email" id="email" name="email" defaultValue="mail@gmail.com" /> </fieldset> <fieldset> <legend>File</legend> <label htmlFor="my-file">Select a file:</label> <input type="file" id="myfile1" name="my-file" multiple /> <input type="file" id="myfile2" name="my-file" multiple /> <input type="file" id="myfile3" name="my-file" multiple /> </fieldset> <fieldset> <legend>Hidden input</legend> <label htmlFor="notHidden">Not hidden input:</label> <input type="text" id="not-hidden-input" name="notHidden" defaultValue="not hidden value" /> <br /> <label htmlFor="hidden" style={{display: 'none'}}>Hidden input:</label> <input type="hidden" id="hidden-input" name="hidden" defaultValue="hidden value" /> </fieldset> <fieldset> <legend>Month</legend> <label htmlFor="bdaymonth">Birthday (month and year):</label> <input type="month" id="bdaymonth" name="bdaymonth" defaultValue="2022-05" /> </fieldset> <fieldset> <legend>Number</legend> <label htmlFor="quantity">Quantity (between 1 and 5):</label> <input type="number" id="quantity" name="quantity" min="1" max="5" defaultValue="3" /> </fieldset> <fieldset> <legend>Range</legend> <label htmlFor="vol">Volume (between 0 and 50):</label> <input type="range" id="vol" name="vol" min="0" max="50" defaultValue="10" /> </fieldset> <fieldset> <legend>Search</legend> <label htmlFor="gsearch">Search Google:</label> <input type="search" id="gsearch" name="gsearch" defaultValue="how to cook pasta" /> </fieldset> <fieldset> <legend>Tel</legend> <label htmlFor="phone">Enter your phone number:</label> <input type="tel" id="phone" name="phone" pattern="[0-9]{3}-[0-9]{2}-[0-9]{3}" defaultValue="123-45-678" /> </fieldset> <fieldset> <legend>Time</legend> <label htmlFor="time">Select a time:</label> <input type="time" id="time" name="time" defaultValue="20:46" /> </fieldset> <fieldset> <legend>Url</legend> <label htmlFor="homepage">Add your homepage:</label> <input type="url" id="homepage" name="homepage" defaultValue="https://myvocab.org" /> </fieldset> <fieldset> <legend>Week</legend> <label htmlFor="week">Select a week:</label> <input type="week" id="week" name="week" defaultValue="2022-W15" /> </fieldset> <button>Submit button</button> <input type="submit" defaultValue="Submit input" /> <input type="reset" defaultValue="Reset to default values" /> <style jsx global>{` * { box-sizing: border-box; } fieldset { margin-bottom: 20px; padding: 10px; } legend { font-weight: 600; } label { margin: 5px; } `}</style> </form> Inputs in HTML <form action="/action" method="POST" autocomplete="off" name="myForm" > <fieldset> <legend>Radios</legend> <input type="radio" id="html" name="fav_language" value="HTML" checked /> <label for="html">HTML</label><br /> <input type="radio" id="css" name="fav_language" value="CSS" /> <label for="css">CSS</label><br /> <input type="radio" id="javascript" name="fav_language" value="JavaScript" /> <label for="javascript">JavaScript</label> </fieldset> <fieldset> <legend>Checkboxes</legend> <input type="checkbox" id="vehicle1" name="vehicles" value="Bike" checked /> <label for="vehicle1"> I have a bike</label><br /> <input type="checkbox" id="vehicle2" name="vehicles" value="Car" checked /> <label for="vehicle2"> I have a car</label><br /> <input type="checkbox" id="vehicle3" name="vehicles" value="Boat" /> <label for="vehicle3"> I have a boat</label> </fieldset> <fieldset> <legend>Text inputs</legend> <label for="fname">First name - readonly:</label><br /> <input type="text" id="fname" name="user" value="John" readonly /><br /> <label for="lname">Last name - disabled:</label><br /> <input type="text" id="lname" name="user" value="Doe" disabled /><br /> <label for="age">age:</label><br /> <input type="number" id="age" name="user" value="35" /> </fieldset> <fieldset> <legend>List input with datalist</legend> <input list="browsers" name="browser" value="Chrome" /> <datalist id="browsers"> <option value="Internet Explorer">Internet Explorer</option> <option value="Firefox">Firefox</option> <option value="Chrome">Chrome</option> <option value="Opera">Opera</option> <option value="Safari">Safari</option> </datalist> </fieldset> <fieldset> <legend>Select</legend> <label for="cars">Choose a car:</label><br /> <select id="cars" name="cars" size="3" multiple> <option value="volvo">Volvo</option> <option value="saab">Saab</option> <option value="fiat">Fiat</option> <option value="audi" selected>Audi</option> </select> </fieldset> <fieldset> <legend>Textarea</legend> <textarea name="message" rows="10" cols="30"> The cat was playing in the garden. </textarea> </fieldset> <fieldset> <legend>Password</legend> <label for="username">Username:</label><br /> <input type="text" id="username" name="login" value="login" /><br /> <label for="pwd">Password:</label><br /> <input type="password" id="pwd" name="pwd" value="password" /> </fieldset> <fieldset> <legend>Color</legend> <label for="favcolor">Select your favorite color:</label> <input type="color" id="favcolor" name="favcolor" value="#ff0000" /> </fieldset> <fieldset> <legend>Date</legend> <label for="birthday">Birthday:</label> <input type="date" id="birthday" name="birthday" min="2010-01-02" max="2025-12-31" value="2022-06-06" /> </fieldset> <fieldset> <legend>Datetime-local</legend> <label for="birthdaytime">Birthday (date and time):</label> <input type="datetime-local" id="birthdaytime" name="birthday time" value="2022-04-08T14:18" /> </fieldset> <fieldset> <legend>Email</legend> <label for="email">Enter your email:</label> <input type="email" id="email" name="email" value="mail@gmail.com" /> </fieldset> <fieldset> <legend>File</legend> <label for="my-file">Select a file:</label> <input type="file" id="myfile1" name="my-file" multiple /> <input type="file" id="myfile2" name="my-file" multiple /> <input type="file" id="myfile3" name="my-file" multiple /> </fieldset> <fieldset> <legend>Hidden input</legend> <label for="notHidden">Not hidden input:</label> <input type="text" id="not-hidden-input" name="notHidden" value="not hidden value" /> <br /> <label for="hidden" style="display: none;">Hidden input:</label> <input type="hidden" id="hidden-input" name="hidden" value="hidden value" /> </fieldset> <fieldset> <legend>Month</legend> <label for="bdaymonth">Birthday (month and year):</label> <input type="month" id="bdaymonth" name="bdaymonth" value="2022-05" /> </fieldset> <fieldset> <legend>Number</legend> <label for="quantity">Quantity (between 1 and 5):</label> <input type="number" id="quantity" name="quantity" min="1" max="5" value="3" /> </fieldset> <fieldset> <legend>Range</legend> <label for="vol">Volume (between 0 and 50):</label> <input type="range" id="vol" name="vol" min="0" max="50" value="10" /> </fieldset> <fieldset> <legend>Search</legend> <label for="gsearch">Search Google:</label> <input type="search" id="gsearch" name="gsearch" value="how to cook pasta" /> </fieldset> <fieldset> <legend>Tel</legend> <label for="phone">Enter your phone number:</label> <input type="tel" id="phone" name="phone" pattern="[0-9]{3}-[0-9]{2}-[0-9]{3}" value="123-45-678" /> </fieldset> <fieldset> <legend>Time</legend> <label for="time">Select a time:</label> <input type="time" id="time" name="time" value="20:46" /> </fieldset> <fieldset> <legend>Url</legend> <label for="homepage">Add your homepage:</label> <input type="url" id="homepage" name="homepage" value="https://myvocab.org" /> </fieldset> <fieldset> <legend>Week</legend> <label for="week">Select a week:</label> <input type="week" id="week" name="week" value="2022-W15" /> </fieldset> <button>Submit button</button> <input type="submit" value="Submit input" /> <input type="reset" value="Reset to default values" /> </form> API route in NextJS // pages\api\action_for_inputs_post.js export default function handler(req, res) { res.status(200).json(req.body) } Output