How to convert a 'string pointer' to a string in Golang?

Question

Is it possible to get the string value from a pointer to a string?

I am using the goopt package to handle flag parsing and the package returns *string only. I want to use these values to call a function in a map.

Example

var strPointer = new(string)
*strPointer = "string"

functions := map[string]func() {
    "string": func(){
        fmt.Println("works")
    },
}  

//Do something to get the string value

functions[strPointerValue]()

returns

./prog.go:17:14: cannot use strPointer (type *string) 
as type string in map index

Solution 1

Dereference the pointer:

strPointerValue := *strPointer

Solution 2

A simple function that first checks if the string pointer is nil would prevent runtime errors:

func DerefString(s *string) string {
    if s != nil {
        return *s
    }

    return ""
}

Comments

[Matteo]

that's correct, however if the pointer string is nil you will have a runtime error

[ram4nd]

What would be a better solution then?

[Archie Yalakki]

@ram4nd if strPointer != nil { strPointerValue := *strPointer }