[go] How to trim leading and trailing white spaces of a string?

Which is the effective way to trim the leading and trailing white spaces of string variable in Go?

package main

import (
    "fmt"
    "strings"
)

func main() {
    fmt.Println(strings.TrimSpace(" \t\n Hello, Gophers \n\t\r\n"))
}

Output: Hello, Gophers

And simply follow this link - https://golang.org/pkg/strings/#TrimSpace

There's a bunch of functions to trim strings in go.

See them there : Trim

Here's an example, adapted from the documentation, removing leading and trailing white spaces :

fmt.Printf("[%q]", strings.Trim(" Achtung  ", " "))

For trimming your string, Go's "strings" package have TrimSpace(), Trim() function that trims leading and trailing spaces.

Check the documentation for more information.

@peterSO has correct answer. I am adding more examples here:

package main

import (
    "fmt"
    strings "strings"
)

func main() { 
    test := "\t pdftk 2.0.2  \n"
    result := strings.TrimSpace(test)
    fmt.Printf("Length of %q is %d\n", test, len(test))
    fmt.Printf("Length of %q is %d\n\n", result, len(result))

    test = "\n\r pdftk 2.0.2 \n\r"
    result = strings.TrimSpace(test)
    fmt.Printf("Length of %q is %d\n", test, len(test))
    fmt.Printf("Length of %q is %d\n\n", result, len(result))

    test = "\n\r\n\r pdftk 2.0.2 \n\r\n\r"
    result = strings.TrimSpace(test)
    fmt.Printf("Length of %q is %d\n", test, len(test))
    fmt.Printf("Length of %q is %d\n\n", result, len(result))

    test = "\r pdftk 2.0.2 \r"
    result = strings.TrimSpace(test)
    fmt.Printf("Length of %q is %d\n", test, len(test))
    fmt.Printf("Length of %q is %d\n\n", result, len(result))   
}

You can find this in Go lang playground too.

A quick string "GOTCHA" with JSON Unmarshall which will add wrapping quotes to strings.

(example: the string value of {"first_name":" I have whitespace "} will convert to "\" I have whitespace \"")

Before you can trim anything, you'll need to remove the extra quotes first:

playground example

// ScrubString is a string that might contain whitespace that needs scrubbing.
type ScrubString string

// UnmarshalJSON scrubs out whitespace from a valid json string, if any.
func (s *ScrubString) UnmarshalJSON(data []byte) error {
    ns := string(data)
    // Make sure we don't have a blank string of "\"\"".
    if len(ns) > 2 && ns[0] != '"' && ns[len(ns)] != '"' {
        *s = ""
        return nil
    }
    // Remove the added wrapping quotes.
    ns, err := strconv.Unquote(ns)
    if err != nil {
        return err
    }
    // We can now trim the whitespace.
    *s = ScrubString(strings.TrimSpace(ns))

    return nil
}

Just as @Kabeer has mentioned, you can use TrimSpace and here is an example from golang documentation:

package main

import (
    "fmt"
    "strings"
)

func main() {
    fmt.Println(strings.TrimSpace(" \t\n Hello, Gophers \n\t\r\n"))
}