PATCH

@HttpPatch
    global static String patchContact(String contactFirstName, String contactLastName) {
        RestRequest req = RestContext.request;
        String contactId = req.requestURI.substring(req.requestURI.lastindexof('/') + 1);
    
        try {
            // Fetch the contact record
            Contact con = [SELECT Id, FirstName, LastName FROM Contact WHERE Id = :contactId LIMIT 1];
            
            // Update contact fields based on provided parameters
            if (contactFirstName != null) {
                con.FirstName = contactFirstName;
            }
            if (contactLastName != null) {
                con.LastName = contactLastName;
            }
    
            // Perform the update
            update con;
    
            // Return the updated contact record
            return JSON.serialize(con);
        } catch (Exception e) {
            return 'Error updating contact: ' + e.getMessage();
        }
    }