cURL Error Code: 7 cURL Error Message: Failed to connect to 127.0.0.1 port 9200: Connection refused cURL Error Code: 7 cURL Error Message: Failed to connect to 127.0.0.1 port 9200: Connection refused
let possibleNumber = "555"
let convertedNumber = Int(possibleNumber)
// convertedNumber 是Int?类型,因为转换有可能会失败。