how can I take input from user in Golang (fmt.scan)

Question

I can not take input from the user in Golang by use fmt.scan().

package main import "fmt" func main() { fmt.Print("Enter text: ") var input string e, _ := fmt.Scanln(&input) fmt.Println(input) fmt.Println(e) }

image of code

After stopping the debugger: image of code The err added to code, but nothing happened.

func main() { fmt.Print("Enter text: ") var input string e, err := fmt.Scanln(&input) if err != nil { fmt.Fprintln(os.Stderr, err) return } fmt.Println(input) fmt.Println(e) }

Image after add err in my Code. What is "not available" in Next line (after my Input value: "51213")

Check for errors. For example, play.golang.org/p/CU9X2Xro7z- — peterSO
– peterSO, Commented Mar 16, 2019 at 4:47
I happen to have this executed on my UNIX terminal and it all worked fine. Would you like to execute it on Powershell using the command go run main.go — tush4r
– tush4r, Commented Mar 16, 2019 at 6:23

Chun Liu · Accepted Answer · 2019-03-16 06:19:21Z

You code has no problem. If you build your code with go build and run the binary directly in a terminal, you will see your code runs.

The problem you hit is because of the Delve and vscode debug console. The vscode debug console doesn't support read from stdin. You can check this issue: Cannot debug programs which read from STDIN for details.

VC Healy · Accepted Answer · 2019-10-21 20:20:22Z

No need for 'e'. Replace it with an underscore and remove the print statement.

 import ( "fmt" "os" ) func main() { fmt.Print("Enter text: \n") var input string _, err := fmt.Scanln(&input) if err != nil { fmt.Fprintln(os.Stderr, err) return } fmt.Println(input) }

Nicolás Gómez · Accepted Answer · 2021-05-27 14:40:51Z

For the record. If you want to input a numeric value, fmt.Scan stores the value in a variable as a string, if you would like perform any mathematical operation with it, you need to convert it either to int or float. A quick example:

func main() { fmt.Println("Type your age: ") var input string _, err := fmt.Scanln(&input) if err != nil { fmt.Fprintln(os.Stderr, err) return } fmt.Printf("%T\n", input) // outputs string inputInt,_ := strconv.Atoi(input) fmt.Printf("%T\n", inputInt) // outputs int fmt.Printf("You were born in %d\n", 2021-inputInt) }

Took me a while to figure it out, hope it helps!

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