Strip all whitespace from a string

Question

What is the fastest way to strip all whitespace from some arbitrary string in Go.

I am chaining two function from the string package:

response = strings.Join(strings.Fields(response),"") 

Anyone have a better way to do this?

Answer 1

Here is some benchmarks on a few different methods for stripping all whitespace characters from a string: (source data):

 BenchmarkSpaceMap-8                     2000       1100084 ns/op      221187 B/op          2 allocs/op BenchmarkSpaceFieldsJoin-8              1000       2235073 ns/op     2299520 B/op         20 allocs/op BenchmarkSpaceStringsBuilder-8          2000        932298 ns/op      122880 B/op          1 allocs/op 

• SpaceMap: uses strings.Map; gradually increases the amount of allocated space as more non-whitespace characters are encountered
• SpaceFieldsJoin: strings.Fields and strings.Join; generates a lot of intermediate data
• SpaceStringsBuilder uses strings.Builder; performs a single allocation, but may grossly overallocate if the source string is mainly whitespace.

package main_test  import (     "strings"     "unicode"     "testing" )  func SpaceMap(str string) string {     return strings.Map(func(r rune) rune {         if unicode.IsSpace(r) {             return -1         }         return r     }, str) }  func SpaceFieldsJoin(str string) string {     return strings.Join(strings.Fields(str), "") }  func SpaceStringsBuilder(str string) string {     var b strings.Builder     b.Grow(len(str))     for _, ch := range str {         if !unicode.IsSpace(ch) {             b.WriteRune(ch)         }     }     return b.String() }  func BenchmarkSpaceMap(b *testing.B) {     for n := 0; n < b.N; n++ {         SpaceMap(data)     } }  func BenchmarkSpaceFieldsJoin(b *testing.B) {     for n := 0; n < b.N; n++ {         SpaceFieldsJoin(data)     } }  func BenchmarkSpaceStringsBuilder(b *testing.B) {     for n := 0; n < b.N; n++ {         SpaceStringsBuilder(data)     } } 

Answer 2

I found the simplest way would be to use strings.ReplaceAll like so:

randomString := "  hello      this is a test" fmt.Println(strings.ReplaceAll(randomString, " ", ""))  >hellothisisatest 

Playground