Which scripting function would be commonly used to modify a field value dynamically on a form?

The function commonly used to modify a field value dynamically on a form is setValue(). This method is part of the client-side scripting capabilities in ServiceNow, which allows developers to interact with form fields and manipulate their values based on specific conditions or events.

When a script utilizes setValue(), it directly updates the value of the specified field in real-time, ensuring that any changes made are immediately reflected on the user's form without needing to refresh or reload the page. This capability is particularly useful in scenarios such as form validation, where you might want to adjust field values based on user input or selections made elsewhere on the form.

In contrast, setField is not a valid function in the context of ServiceNow’s client-side scripting. Similarly, getValue() is used to retrieve the current value of a field rather than modify it, and updateField does not exist in the client-side API for manipulating field values. Therefore, setValue() stands out as the correct choice when dealing with dynamic updates of field values on ServiceNow forms.