1 package main
 2 
 3 import (
 4     "fmt"
 5     "strconv"
 6     "os"
 7     "bufio"
 8 )
 9 
10 //for的条件里不需要括号
11 //for的条件里可以省略初始条件，结束条件和递增表达式,三个省略就是死循环
12 //没有while语句，只留结束条件等于while
13 
14 func convertToBin ( n int ) string {
15     result := ""
16     for ; n > 0; n /= 2 {
17         lsb := n % 2
18         result = strconv.Itoa( lsb ) + result
19     }
20     return  result
21 }
22 
23 func printFlie( filename string) {
24     file, err := os.Open( filename)
25     if err !=nil{
26         panic(err)
27     }
28 
29     scanner := bufio.NewScanner( file)
30 
31     for scanner.Scan() {  //只有结束条件
32         fmt.Println(scanner.Text())
33     }
34 }
35 
36 
37 func main() {
38     fmt.Println(
39         convertToBin(5) , //101
40         convertToBin(13), //1011 --> 1101
41     )
42 
43     printFlie("abc.txt")
44 }