I have two inputs with their respective ID's, I would like the alert to display the value entered in the selected field, so if I am typing in field 1 it will display the value in the alert referring to field 1 if I am typing in field 2 to display the value in the alert for field 2.
Idea Update
I saw the code from JuniorNunes7 and I had an idea and would like to do something new, sorry. See the image:
Thank you
I think this is what you need according to the description of your image, I just did not put any alerts, but I imagine you were just trying to test ...
$("#principal").on('change keyup paste', function(){
var input = $('.check:checked').val();
$("#"+input).val($(this).val());
});<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script><div><label>Master</label><inputid="principal" type="text">
</div>
<br />
<div>
<input type="radio" name="check" class="check" value="campo1" checked>
<label>campo1</label>
<input class="campo" id="campo1" name="campo1" type="text" readonly>
</div>
<div>
<input type="radio" name="check" class="check" value="campo2">
<label>campo2</label>
<input class="campo" id="campo2" name="campo2" type="text" readonly>
</div> To show something whenever the input value is changed (typed, deleted, pasted), you can use the onInput event.
$('#input-id').on('input', function() {
alert($(this).val());
});
It is also possible to use change , it will be fired only when the user "deselects" the input.
$('#input-id').on('change', function() {
alert($(this).val());
});