练习golang string常用操作,备份

类型转换

比较对比

搜索 查找 统计

替换

删除过滤

大小写转换

前缀后缀

字符串分割

拼接

3中拼接字符串方式对比

func main() {
 fmt.Println("字符串测试")
 fmt.Println("字符串转化")
 //获取程序运行的操作系统平台下 int 类型所占的位数,如:strconv.IntSize。
 //strconv.IntSize
 fmt.Println("将字符串转换为 int 型。")
 var trastr01 string = "100"
 traint01, err_tra := strconv.Atoi(trastr01)
 if err_tra != nil {
 fmt.Println(err_tra)
 } else {
 fmt.Println(traint01)
 }
 fmt.Println("将字符串转换为 float64 型")
 var trastr02 string = "100.55"
 trafloat01, err_float := strconv.ParseFloat(trastr02, 10)
 if err_float != nil {
 fmt.Println(err_float)
 } else {
 fmt.Println(trafloat01)
 }
 trastr03 := strconv.Itoa(99)
 fmt.Println("int 转字符安 " + trastr03)
 var str01 string = "hello,world"
 str02 := "你好,世界"
 fmt.Println(str01)
 fmt.Println(str02)
 //
 //字符串比较
 com01 := strings.Compare(str01, str02)
 if com01 == 0 {
 fmt.Println("相等")
 } else {
 fmt.Println("不相等 " + string(com01))
 }
 fmt.Println(com01)
 //查找 包含
 var isCon bool = strings.Contains(str01, "hello")
 fmt.Println(isCon) //true
 //查找位置
 var theIndex int = strings.Index(str01, ",")
 fmt.Println(theIndex) //5
 fmt.Println(strings.Index(str01, "haha")) //不存在返回-1
 lastIndex := strings.LastIndex(str01, "o")
 fmt.Println("在字符串中最后出现位置的索引 " + strconv.Itoa(lastIndex)) //7
 //-1 表示字符串 s 不包含字符串
 //统计给定子串sep的出现次数, sep为空时, 返回1 + 字符串的长度
 fmt.Println(strings.Count("cheeseeee", "ee")) // 3
 fmt.Println(strings.Count("five", "")) // 5
 // 重复s字符串count次, 最后返回新生成的重复的字符串
 fmt.Println("hello " + strings.Repeat("world ", 10))
 fmt.Println("替换")
 // 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
 var str03 string = "/Users//Documents/GOPatch/src/MyGO/config/TestString/"
 str04 := strings.Replace(str03, "/", "**", -1)
 str05 := strings.Replace(str03, "/", "**", 4)
 fmt.Println(str04) //**Users****Documents**GOPatch**src**MyGO**config**TestString**
 fmt.Println(str05) //**Users****Documents**GOPatch/src/MyGO/config/TestString/
 fmt.Println("删除字符串的开头和尾部")
 fmt.Println("删除两头的/ = " + strings.Trim(str03, "/")) //Users//Documents/GOPatch/src/MyGO/config/TestString
 fmt.Println("删除左边的/ = " + strings.TrimLeft(str03, "/")) //Users//Documents/GOPatch/src/MyGO/config/TestString/
 //还有 TrimRight
 str06 := strings.TrimSpace(" hello hao hao hao ")
 fmt.Println("删除开头末尾的空格 =" + str06) //'hello hao hao hao'
 fmt.Println("大小写")
 str07 := "hello hao hao hao"
 fmt.Println(strings.Title(str07)) //Hello Hao Hao Hao
 fmt.Println(strings.ToLower(" Hello Hao Hao Hao")) // hello hao hao hao
 fmt.Println(strings.ToUpper(str07)) //HELLO HAO HAO HAO
 //前缀 后缀
 fmt.Println(strings.HasPrefix("Gopher", "Go")) // true
 fmt.Println(strings.HasSuffix("Amigo", "go")) // true
 fmt.Println("字符串分割")
 fieldsStr := " hello it's a nice day today "
 //根据空白符分割,不限定中间间隔几个空白符
 fieldsSlece := strings.Fields(fieldsStr)
 fmt.Println(fieldsSlece) //[hello it's a nice day today]
 for i, v := range fieldsSlece {
 fmt.Printf("下标 %d 对应值 = %s \n", i, v)
 }
 for i := 0; i < len(fieldsSlece); i++ {
 fmt.Println(fieldsSlece[i])
 }
 //根据特定字符分割
 slice01 := strings.Split("q,w,e,r,t,y,", ",")
 fmt.Println(slice01) //[q w e r t y ]
 fmt.Println(cap(slice01)) //7 最后多个空""
 for i, v := range slice01 {
 fmt.Printf("下标 %d 对应值 = %s \n", i, v)
 }
 //拼接
 //Join 用于将元素类型为 string 的 slice, 使用分割符号来拼接组成一个字符串:
 var str08 string = strings.Join(fieldsSlece, ",")
 fmt.Println("Join拼接结果=" + str08) //hello,it's,a,nice,day,today
 fmt.Println("------------对比字符串拼接效率----------------")
 var buffer bytes.Buffer
 start := time.Now()
 for i := 0; i < 100000; i++ {
 buffer.WriteString("test is here\n")
 }
 buffer.String() // 拼接结果
 end := time.Now()
 fmt.Println("Buffer time is ", end.Sub(start).Seconds())
 start = time.Now()
 str := ""
 for i := 0; i < 100000; i++ {
 str += "test is here\n"
 }
 end = time.Now()
 fmt.Println("+= time is ", end.Sub(start).Seconds())
 start = time.Now()
 var sl []string
 for i := 0; i < 100000; i++ {
 sl = append(sl, "test is here\n")
 }
 strings.Join(sl, "")
 end = time.Now()
 fmt.Println("Join time is", end.Sub(start).Seconds())
 /*
 Buffer time is 0.00388283
 += time is 11.730007558
 Join time is 0.016644653
 */
}

本文来自:简书

感谢作者:正为疯狂

查看原文:golang 字符串常用操作(go练习代码)

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