// // Foundation+.swift // IOS_study // // Created by CC-star on 2025/6/29. // import Foundation extension String { var isBlank: Bool { self.isEmpty || self.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty//没有输入或者输入空格 } var trimmed: String { self.trimmingCharacters(in: .whitespacesAndNewlines) } } extension Date { var daysFromNow: Int { Calendar.current.dateComponents([.day], from: self, to: .now).day ?? 0//??空合运算符 } // let date = Date() // print(date.string(withFormat: "yyyy/MM/dd HH:mm")) // 2023/08/24 16:21 // print(date.string(withFormat: "yyyy/MM/dd hh:mm")) // 2023/08/24 04:21 var toStr: String { let year = Calendar.current.component(.year, from: self) let currentYear = Calendar.current.component(.year, from: Date()) let dateFormatter = DateFormatter() dateFormatter.dateFormat = (year == currentYear) ? "M-d" : "yyyy-M-d" return dateFormatter.string(from: self) } }