Which function would be used to clear a form field in a client script?

The function that would be used to clear a form field in a client script is g_form.setValue('fieldname', ''). This method is part of the GlideForm API within ServiceNow, which allows developers to manipulate form fields dynamically on the client side.

When you use g_form.setValue('fieldname', '') and provide an empty string as the second argument, it effectively clears the content of the specified form field, resetting it to a blank state. This is useful in scenarios where you want to reset fields based on user interactions or specific conditions occurring within the form.

This approach not only clears the field visually but also ensures that the value being submitted is an empty string. In contrast, other options listed do not represent valid client script methods for clearing form fields in ServiceNow. For instance, resetField() and clearField() do not exist in the ServiceNow API, while g_form.clearValue() is also not a recognized method. Therefore, g_form.setValue('fieldname', '') is the correct choice for this operation.