Understanding Scanf in Go

huangapple
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英文:

Understanding Scanf in Go

问题

我不确定如何使用Scanf函数。假设我想在扫描时输入数字10。那么输出应该是0xA吗？

另外，我如何在函数中使用两个或更多的扫描参数（例如fmt.Scanf("%x", &e, &f, &g)）？

  1. package main
  3. import (
  4. 	"fmt"
  5. )
  7. func main() {
  8. 	var e int
  10. 	fmt.Scanf("%#X", &e)
  11. 	fmt.Println(e)
  12. }

请注意，我只会翻译代码部分，不会回答关于代码的问题。

英文:

I am not sure how to use Scanf function. Let's say I want to input number 10 on scan. By doing that, shouldn't the output be 0xA?

Also, how do I use the function with two or more scan arguments (e.g. fmt.Scanf("%x", &e, &f, &g))?

  1. package main
  3. import (
  4. 	"fmt"
  5. )
  7. func main() {
  9.     var e int
  11. 	fmt.Scanf("%#X", &e)
  12. 	fmt.Println(e)
  14. }

答案1

得分: 16

你需要首先将输入作为整数进行处理，然后打印其十六进制值：

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"os"
  6. )
  8. func main() {
  10. 	var e int
  12. 	fmt.Scanf("%d", &e)
  13. 	fmt.Fprintf(os.Stdout, "%#X\n", e)
  15. }

输出结果为：

  1. go run main.go 
  2. 10
  3. 0XA

对于多个输入：

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"os"
  6. )
  8. func main() {
  10. 	var e int
  11. 	var s string
  13. 	fmt.Scanf("%d %s", &e, &s)
  14. 	fmt.Fprintf(os.Stdout, "%#X \t%s\n", e, s)
  16. }

输出结果为：

  1. go run main.go
  2. 10 hello
  3. 0XA 	hello

更新：fmt.Scanf() vs fmt.Scan()

Scan可以循环读取输入：

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"os"
  6. )
  8. func main() {
  10. 	var e int
  11. 	var f int
  12. 	var g int
  14. 	fmt.Scan(&e, &f, &g)
  15. 	fmt.Fprintf(os.Stdout, "%d - %d - %d", e, f, g)
  16. }

输出结果为：

  1. go run main.go
  2. 10
  3. 11
  4. 12
  5. 10 - 11 - 12

Scanf可以从格式化字符串中进行过滤：

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"os"
  6. )
  8. func main() {
  10. 	var e int
  11. 	var f int
  13. 	fmt.Scanf("%d Scanf %d", &e, &f)
  14. 	fmt.Fprintf(os.Stdout, "%d - %d", e, f)
  15. }

输出结果为：

  1. go run main.go 
  2. 10 Scanf 11
  3. 10 - 11
英文:

You have to first take your input as an int and then print the hex value :

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"os"
  6. )
  8. func main() {
  10. 	var e int
  12. 	fmt.Scanf("%d", &e)
  13. 	fmt.Fprintf(os.Stdout, "%#X\n", e)
  15. }

Output is :

  1. go run main.go 
  2. 10
  3. 0XA

For multiple inputs :

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"os"
  6. )
  8. func main() {
  10. 	var e int
  11. 	var s string
  13. 	fmt.Scanf("%d %s", &e, &s)
  14. 	fmt.Fprintf(os.Stdout, "%#X \t%s\n", e, s)
  16. }

Output is :

  1. go run main.go
  2. 10 hello
  3. 0XA 	hello

Update : fmt.Scanf() vs fmt.Scan()

Scan is able to loop :

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"os"
  6. )
  8. func main() {
  10. 	var e int
  11. 	var f int
  12. 	var g int
  14. 	fmt.Scan(&e, &f, &g)
  15. 	fmt.Fprintf(os.Stdout, "%d - %d - %d", e, f, g)
  16. }

Output is :

  1. go run main.go
  2. 10
  3. 11
  4. 12
  5. 10 - 11 - 12

Scanf is able to """filter""" from a formated string :

  1. package main
  3. import (
  4. 	"fmt"
  5. 	"os"
  6. )
  8. func main() {
  10. 	var e int
  11. 	var f int
  13. 	fmt.Scanf("%d Scanf %d", &e, &f)
  14. 	fmt.Fprintf(os.Stdout, "%d - %d", e, f)
  15. }

Output is :

  1. go run main.go 
  2. 10 Scanf 11
  3. 10 - 11

huangapple
  • 本文由 发表于 2017年5月1日 00:56:35
  • 转载请务必保留本文链接：https://go.coder-hub.com/43708943.html
  • go
  • scanf
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