Below is example to count words in string with Golang. You can run this code snippet online via Golang Playground.

package main

import (
  "fmt"
  "strings"
)

func wordCount(s string) map[string]int {

  // create map with string as key and integer as value
  result := make(map[string]int)

  // string.Fields splits the strings s and returns as a slice.
  //
  // Iterate with range so that we can assign result variable
  // with substring as key and the word occurences as value.
  //
  // Default value of result[val] is 0, so we can just add one.
  for _, val := range strings.Fields(s) {
    result[val] += 1
  }

  return result
}

func main() {
  fmt.Println(wordCount("hello world hello"))
  fmt.Println(wordCount("world hello world aloha"))
}

Output

map[hello:2 world:1]
map[aloha:1 hello:1 world:2]