How to remove redundant spaces/whitespace from a string in Golang?

Question

I was wondering how to remove:

• All leading/trailing whitespace or new-line characters, null characters, etc.
• Any redundant spaces within

Answer 1

Avoiding to use time wasting regexp or external library
I've choose to use plain golang instead of regexp, cause there are special character that are not ASCII in every language.

Go Golang!

func RemoveDoubleWhiteSpace(str string) string {
    var b strings.Builder
    b.Grow(len(str))
    for i := range str {
        if !(str[i] == 32 && (i+1 < len(str) && str[i+1] == 32)) {
            b.WriteRune(rune(str[i]))
        }
    }
    return b.String()
}

And the related test

func TestRemoveDoubleWhiteSpace(t *testing.T) {
    data := []string{`  test`, `test  `, `te  st`}
    for _, item := range data {
        str := RemoveDoubleWhiteSpace(item)
        t.Log("Data ->|"+item+"|Found: |"+str+"| Len: ", len(str))
        if len(str) != 5 {
            t.Fail()
        }
    }
}