I am new at javascript,and i was trying and trying with this but something is wrong,i wanna make the checked radio button red, black, green and blue but I don't know how to use JavaScript
<table>
<B id="grandezza1">Colore Testo :</B>
</table>
<p style="color:blue" id="colore">
<br> Nero  
<INPUT type="radio" name="colore" value="Nero" onclick="cambiaColore()" checked>
<BR> Rosso
<INPUT type="radio" name="colore" value="Rosso" onclick="cambiaColore()">
<BR> Verde
<INPUT type="radio" name="colore" value="Verde" onclick="cambiaColore()">
<BR> Blue  
<INPUT type="radio" name="colore" value="Blue" onclick="cambiaColore()">
<BR>
</P>function cambiaColore(){
document.getElementById("area").style.color = $('input[name="radioC"]:checked').val();
}
You cannot change the colour of a radio button. You can change the colour of the label
In your code, you are mixing DOM (document....) with jQuery ($(...)) that is not a great idea. You were also missing the jQuery library.
Also your name was colore and not radioC
Here I delegate the click from the container
I also fixed your invalid HTML.
const cambiaColore = () => {
document.querySelectorAll("#colore input[type=radio]").forEach(rad => rad.closest("label").classList.toggle(rad.value, rad.checked))
}
document.getElementById("colore").addEventListener("click", cambiaColore);
cambiaColore(); // initialise.Nero {
background-color: black;
color: white
}
.Rosso {
background-color: red;
color: yellow
}
.Verde {
background-color: green;
color: yellow
}
.Blu {
background-color: blue;
color: yellow
}<b id="grandezza1">Colore Testo :</b>
<p style="color:blue" id="colore">
<label>Nero <input type="radio" name="colore" value="Nero" checked /></label><br/>
<label>Rosso <input type="radio" name="colore" value="Rosso" /></label><br/>
<label>Verde <input type="radio" name="colore" value="Verde" /></label><br/>
<label>Blu <input type="radio" name="colore" value="Blu" /></label><br/>
</p>