我建议使用
URLComponents
var components = URLComponents(string: "http://mycompany.com")!
components.path = "/sap/opu/odata/SAP/ZTM_FOR_MOBILITY_SRV/BusinessPartnerSet('\(businessPartners[myIndex].partnerId)')/"
components.queryItems = [URLQueryItem(name: "$format", value:"json")]
if let url = components.url {
print(url)
// or if you need the string
print(url.absoluteString)
}