zoukankan      html  css  js  c++  java
  • There is no type initializer in Swift----One answer is to use static, it is the same as class final.

    “Unlike stored instance properties, you must always give stored type properties a default value. This is because the type itself does not have an initializer that can assign a value to a stored type property at initialization time.”

    Excerpt From: Apple Inc. “The Swift Programming Language.” iBooks


    You could use a type property which default value is a closure. So the code in the closure would be executed when the type property (or class variable) is set.

    But class stored properties not yet supported (tested in Xcode 8).

    One answer is to use static, it is the same as class final.

    Good link for that is

    Setting a Default Property Value with a Closure or Function

    Excerpt From: Apple Inc. “The Swift Programming Language.” iBooks


    Code example:

    Prints

    start

    setting default property value with a closure

    So it is lazy evaluated.

    https://stackoverflow.com/questions/24137212/initialize-class-method-for-classes-in-swift

  • 相关阅读:
    Python 递归
    Python 面向过程编程
    Python 协程函数
    Python-第三方库requests详解
    Python 三元表达式
    linux copy
    centos 安装软件
    mysql 权限
    mysql 权限 备份
    android 开发
  • 原文地址:https://www.cnblogs.com/feng9exe/p/11225790.html
Copyright © 2011-2022 走看看