form/input field-specific validation in object methods (php) - php

Question

Lets say we have a regular HTML form with several input fields:
<form>
<input type="text" name="user">
<input type="email" name="email">
<input type="password" name="password">
<input type="number" name="amount">
<buttont type="submit">Send</button>
</form>
That form is transmitted and then handled in a class method:
function example($user, $password, $email, $amount) {
// Check for all input fields
return "error text";
}
So far so good - that works well if you want to display one generic error message nearby the form.
// <form> ... </form>
<span style="color:red;">Generic error message</span>
But what if you want to display multiple error messages; one for each field?
<form>
<input type="text" name="user">
<span style="color:red;">user error</span>
<input type="email" name="email">
<span style="color:red;">email error</span>
<input type="password" name="password">
<span style="color:red;">password error</span>
<input type="number" name="amount">
<span style="color:red;">amount error</span>
</form>
Is there an efficient way to achieve this? I thought about collecting error messages in an array (within the method), return the array and then check with isset() if there is an error.
$errors = example($user, $password, $email, $amount);
<form>
<input type="text" name="user">
<?php
if(isset($errors["user"])) {
?>
<span style="color:red;">user error</span>
<?php
}
?>
</form>
That attempt, however, is bloating the code. Especially when we're talking about multiple forms and tens of different methods. Is there a better solution to achieve what i want?