Go语言学习笔记，四

10.字符串原理解析

a.字符串底层就是一个byte数组，所以可以和[]byte类型互相转换

b.字符串之中的字符是不能修改的,想要修改只能用byte切片来修改

  1: package main

  2: 

  3: import (

  4:     "fmt"

  5: )

  6: 

  7: func testString(){

  8:     var str string = "hello"

  9:     fmt.Printf("str[0]=%c len(str)=%d\n", str[0], len(str))

 10:     for index, val := range str {

 11:             fmt.Printf("str[%d]=%c\n", index, val)

 12:     }

 13:     // 定义byte切片

 14:     var byteSlice []byte

 15:     byteSlice = []byte(str)

 16:     byteSlice[0] = 'o'

 17:     str = string(byteSlice)

 18:     fmt.Println(str)

 19: }

 20: 

 21: func main()  {

 22:     testString()

 23: }

c.字符串是byte字节组成,所以字符串的长度是byte字节的长度

d.rune类型用来表示utf8字符，一个rune字符由1个或多个byte组成

  1: var b rune = '中'

  2:     str = "中文123"

  3:     fmt.Printf("b=%c\n", b)

  4:     var runeSlice []rune

  5:     runeSlice = []rune(str)

  6:     fmt.Printf("str长度=%d len(str)=%d\n", len(runeSlice), len(str))

几个关于字符串的练习：

test1:对英文字符串进行逆序

  1: func test1(){

  2:     var str = "hello"

  3:     // var bytes []byte = []byte(str)

  4:     bytes := []byte(str)

  5:     for i :=0; i < len(str)/2; i++ {

  6:             tmp := bytes[len(str)-i-1]

  7:             bytes[len(str)-i-1] = bytes[i]

  8:             bytes[i] = tmp

  9:     }

 10:     str = string(bytes)

 11:     fmt.Println(str)

 12: }

test2:对包含中文的字符串进行逆序

  1: func test2(){

  2:     var str = "hello,你好"

  3:     runes := []rune(str)

  4: 

  5:     for i:=0; i < len(runes)/2; i++ {

  6:             tmp := runes[len(runes)-i-1]

  7:             runes[len(runes)-i-1] = runes[i]

  8:             runes[i] = tmp

  9:     }

 10:     str = string(runes)

 11:     fmt.Println(str)

 12: }

test3:判断一个字符串是否是回文

  1: func test3() {

  2:     var str = "上海自来水来自海上"

  3:     runes := []rune(str)

  4:     for i:=0; i < len(runes)/2; i++ {

  5:             tmp := runes[len(runes)-i-1]

  6:             runes[len(runes)-i-1] = runes[i]

  7:             runes[i] = tmp

  8:     }

  9:     str_2 := string(str)

 10:     if str == str_2 {

 11:             fmt.Println("yes")

 12:     }else{

 13:             fmt.Println("no")

 14:     }       

 15: }