radio selected
snippet in php

html radio button checked

user7023

  <input type="radio" id="huey" name="drone" value="huey"
         checked> 
<!-- https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/radio-->

input radio html

user5072

<form>
  <p>Veuillez choisir la meilleure méthode pour vous contacter :</p>
  <div>
    <input type="radio" id="contactChoice1"
     name="contact" value="email">
    <label for="contactChoice1">Email</label>

    <input type="radio" id="contactChoice2"
     name="contact" value="telephone">
    <label for="contactChoice2">Téléphone</label>

    <input type="radio" id="contactChoice3"
     name="contact" value="courrier">
    <label for="contactChoice3">Courrier</label>
  </div>
  <div>
    <button type="submit">Envoyer</button>
  </div>
</form>

radio selected

user4669

//checked
  <input type="radio" id="huey" name="drone" value="huey"
         checked>