Go语言圣经-函数多返回值习题详解编程语言

package main 
 
import ( 
        "fmt" 
        "golang.org/x/net/html" 
        "net/http" 
        "os" 
        "strings" 
) 
/* 
练习 5.5： 实现countWordsAndImages。（参考练习4.9如何分词） 
*/ 
func main() { 
        words, images, _ := CountWordsAndImages(os.Args[1]) 
        fmt.Printf("文字：%d,图片：%d /n",words,images) 
} 
 
// CountWordsAndImages does an HTTP GET request for the HTML 
// document url and returns the number of words and images in it. 
func CountWordsAndImages(url string) (words, images int, err error) { 
        resp, err := http.Get(url) 
        if err != nil { 
                return 
        }    
        doc, err := html.Parse(resp.Body) 
        resp.Body.Close() 
        if err != nil { 
                err = fmt.Errorf("parsing HTML: %s", err) 
                return 
        }    
        words, images = countWordsAndImages(doc) 
        //bare return 
        return 
} 
func countWordsAndImages(n *html.Node) (words, images int) { 
 
        texts, images := visit3(nil,0, n) 
        for _, v := range texts { 
                v = strings.Trim(strings.TrimSpace(v), "/r/n") 
                if v == "" { 
                        continue 
                }    
                words += strings.Count(v, "")  
        }    
        //bare return 
        return 
} 
//递归循环html 
func visit3(texts []string, imgs int, n *html.Node) ([]string, int) { 
        //文本 
        if n.Type == html.TextNode { 
                texts = append(texts, n.Data) 
        }    
        //图片 
        if n.Type == html.ElementNode && (n.Data == "img") { 
                imgs++ 
        } 
        for c := n.FirstChild; c != nil; c = c.NextSibling { 
                if c.Data == "script" || c.Data == "style" { 
                        continue 
                } 
 
                texts,imgs = visit3(texts, imgs, c) 
        } 
        //多返回值 
        return texts, imgs 
}