Question

您好以下Go程序中有两个问题 1.我无法使用Scanf或Scanln读取空格分隔的字符串所以我添加了一个格式化的字符串“％q”来使用双引号读取空格分隔的字符串。有空格读取字符串的替代方法吗？

package main
import
(
    "fmt"
    "strings"
)

type details struct{
    DataType string
    Table string

}
func main(){
    dt := details{}
    fmt.Println("Enter the DataType")
    fmt.Scanf("%q" ,&dt.DataType )
    for strings.TrimSpace(dt.DataType) == "" {
        fmt.Println("Enter the DataType")
        fmt.Scanln(&dt.DataType)
    }
    //fmt.Println(dt.DataType)
    fmt.Println("Enter the Table")
    fmt.Scanln(&dt.Table)
    for strings.TrimSpace(dt.Table) == "" {
        fmt.Println("Enter a valid Table name ")
        fmt.Scanln(&dt.Table)
    }
}

控制台输出如下，

VenKats-MacBook-Air:ColumnCreator venkat$ go run test.go
Enter the DataType
"rid bigint not null"
Enter the Table
Enter a valid Table name

第二个问题是为什么控制流在没有等待用户输入的情况下进入第二个for循环。具有“％q”的Scanf是否返回了carraige返回。任何帮助将不胜感激

Answer 1

也许是这样的......

package main

import (
    "bufio"
    "fmt"
    "os"
    "strings"
)

type details struct {
    DataType string
    Table    string
}

func main() {
    dt := details{}
    cin := bufio.NewReader(os.Stdin)
    for {
        fmt.Println("Enter the DataType")
        text, err := cin.ReadString('\n') // reads entire string up until the /n which is the newline deliminator
        if strings.TrimSpace(text) == "" { // check to see if the input is empty
            continue
        }
        if err == nil { // if the input is not empty then the control got this far and now we just have to check for error, assign the data, and break out of the loop .. repeat for the second input. If this is going to be something you do alot refactor the input section.
            dt.DataType = text
            break
        } else {
            fmt.Printf("An error as occured: %s\n", err.Error())
        }
    }
    for {
        fmt.Println("Enter the Table")
        text, err := cin.ReadString('\n')
        if strings.TrimSpace(text) == "" {
            continue
        }
        if err == nil {
            dt.Table = text
            break
        } else {
            fmt.Printf("An error as occured: %s\n", err.Error())
        }
    }
    fmt.Printf("%+v\n", dt)
    return
}

重构代码示例：

package main

import (
    "bufio"
    "fmt"
    "os"
    "strings"
)

type details struct {
    DataType string
    Table    string
}

func getInput(message string, reader bufio.Reader) (input string) {
    for {
        fmt.Println(message)
        input, err := reader.ReadString('\n')
        if strings.TrimSpace(input) == "" {
            continue
        }
        if err == nil {
            break
        } else {
            fmt.Printf("An error as occured: %s\n", err.Error())
        }
    }
    return
}

func main() {
    dt := details{}
    cin := bufio.NewReader(os.Stdin)
    t := getInput("Enter the DataType", *cin)
    dt.DataType = t
    t = getInput("Enter the Table", *cin)
    dt.Table = t
    fmt.Printf("Seeing what my data looks like  %+v\n", dt)
    return
}

阅读Golang 1.8中的Space Seperated Strings

1 个答案: