Example to creating multiple titles for headers in section given different layout options

SectionTitleEnumExample.swift

enum SectionTitle: String {
    case a = "a"
    case b = "b"
    case c = "c"
    case d = "d"
    init?(section: Int, hasB: Bool = false, hasD: Bool = false) {
        if hasD {
            switch section {
            case 0: self = .a
            case 1: self = .b
            case 2: self = .c
            case 3: self = .d
            default: return nil
            }
        } else {
            switch section {
            case 0: self = .a
            case 1:
                if hasB {
                    self = .b
                } else {
                    self = .c
                }
            case 2:
                self = .c
            default: return nil
            }
        }
    }
}

UIViewController.swift

func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
    let hasB = true
    let hasD = false
    let title = SectionTitle(section: section, hasB: hasB, hasD: hasD)
    return title?.rawValue ?? ""
}