"guard"相比"if...else"可读性更强

最新推荐文章于 2023-07-07 00:04:09 发布

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最新推荐文章于 2023-07-07 00:04:09 发布

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分类专栏： Swift代码

本文链接：https://blog.youkuaiyun.com/qq_33033983/article/details/52075088

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//
//  guard.swift
//
//  Created by chenzhen on 16/7/30.
//  From 大连东软信息学院
//  Copyright © 2016年 zhen7216. All rights reserved.
//

import Foundation


struct Blog {
    let name: String?
    let URL: String?
    let Author: String?
}
func ifLongStyleBlog(blog: Blog) {
    
    if let blogName = blog.name {
        print("这篇博客名：\(blogName)")
        
        if let blogAuthor = blog.Author {
            print("这篇博客由\(blogAuthor)写的")
            
            if let blogURL = blog.URL {
                print("这篇博客网址：\(blogURL)")
            } else {
                print("这篇博客没有网址！")
            }
        } else {
            print("这篇博客没有作者！")
        }
    } else {
        print("这篇博客没有名字！")
    }
    
}


func guardLongStyleBlog(blog: Blog) {
    
    guard let blogName = blog.name else {
        print("这篇博客没有名字！")
        return
    }
    
    print("这篇博客名：\(blogName)")
    
    guard let blogAuthor = blog.Author else {
        print("这篇博客没有作者")
        return
    }
    
    print("这篇博客由\(blogAuthor)写的")
    
    guard let blogURL = blog.URL else {
        print("这篇博客没有网址！")
        return
    }
    
    print("这篇博客网址：\(blogURL)")
}


let blog1 = Blog(name: nil, URL: nil, Author: "Tom")
let blog2 = Blog(name: "chenzhen'blog", URL: "1229383755@qq.com", Author: "chenzhen")



guardLongStyleBlog(blog1)
print("*************************")
guardLongStyleBlog(blog2)

运行结果：