golang之字符串处理

web开发时常要对字符串处理，特记录以下函数。
copy自：build-web-application-with-golang

• 1. 字符串s中是否包含substr
     func Contains(s, substr string) bool

fmt.Println(strings.Contains("seafood", "foo"))
fmt.Println(strings.Contains("seafood", "bar"))
fmt.Println(strings.Contains("seafood", ""))
fmt.Println(strings.Contains("", ""))
//Output:
//true
//false
//true
//true

• 2.字符串链接
  func Join(a []string, sep string) string

s := []string{"foo", "bar", "baz"}
fmt.Println(strings.Join(s, ", "))
//Output:foo, bar, baz      

• 3.在字符串s中查找sep所在的位置，返回位置值，找不到返回-1
  func Index(s, sep string) int

fmt.Println(strings.Index("chicken", "ken"))
fmt.Println(strings.Index("chicken", "dmr"))
//Output:4
//-1

• 4.重复s字符串count次，最后返回重复的字符串
  func Repeat(s string, count int) string

fmt.Println("ba" + strings.Repeat("na", 2))
//Output:banana

• 5.在s字符串中，把old字符串替换为new字符串，n表示替换的次数，小于0表示全部替换
  func Replace(s, old, new string, n int) string

fmt.Println(strings.Replace("oink oink oink", "k", "ky", 2))
fmt.Println(strings.Replace("oink oink oink", "oink", "moo", -1))
//Output:oinky oinky oink
//moo moo moo

• 6.把s字符串按照sep分割，返回slice
  func Split(s, sep string) []string

fmt.Printf("%q\n", strings.Split("a,b,c", ","))
fmt.Printf("%q\n", strings.Split("a man a plan a canal panama", "a "))
fmt.Printf("%q\n", strings.Split(" xyz ", ""))
fmt.Printf("%q\n", strings.Split("", "Bernardo O'Higgins"))
//Output:["a" "b" "c"]
//["" "man " "plan " "canal panama"]
//[" " "x" "y" "z" " "]
//[""]

• 7.在s字符串的头部和尾部去除cutset指定的字符串
  func Trim(s string, cutset string) string

fmt.Printf("[%q]", strings.Trim(" !!! Achtung !!! ", "! "))
//Output:["Achtung"]

• 8.去除s字符串的空格符，并且按照空格分割返回slice
  func Fields(s string) []string

fmt.Printf("Fields are: %q", strings.Fields("  foo bar  baz   "))
//Output:Fields are: ["foo" "bar" "baz"]