Golang字符串函数认识（二）

package main
import (
    "fmt"
    "strings"
    
)


func main(){
    //返回字符在指定字符串中最后一次出现的位置
    last_index := strings.LastIndex("Hello World", "l")
    fmt.Printf("last_index=%v
", last_index)  //last_index=9


    //字符串替换,类似php的str_replace，但是go的 貌似更强大
    //strings.Replace("hello,welcome come go world,go to go", "golang", n)
    //将指定的字符串替换成另一个子串，可以指定希望替换几个，如果n=-1表示全部替换
    new_str := strings.Replace("hello,welcome come go world,go to go", "go", "golang", 1)
    fmt.Printf("new_str=%v
", new_str)
    //last_index=9new_str=hello,welcome come golang world,golang to golang

    new_str = strings.Replace("hello,welcome come go world,go to go", "go", "golang", 1)
    fmt.Printf("new_str=%v
", new_str)
    //last_index=9new_str=hello,welcome come golang world,go to go


    //将字符串按照指定字符分割成数组，类似php中的explode
    str2arr := strings.Split("hello,golang,I love you", ",")
    fmt.Printf("str2arr类型%T,%v
", str2arr, str2arr) //str2arr类型[]string,[hello golang I love you]
    for i := 0; i < len(str2arr); i++ {
        fmt.Printf("str2arr[%v]=%v
", i, str2arr[i])
    }
    //str2arr[0]=hello
    //str2arr[1]=golang
    //str2arr[2]=I love you


    //将字符串进行大小写转换
    str := "hello Golang"
    str = strings.ToLower(str)  //全部转换为小写
    fmt.Printf("last=%v", str)  //last=hello golang
    str = strings.ToUpper(str)  //全部转换为大写
    fmt.Printf("last=%v
", str)  //last=HELLO GOLANG

    //将字符串两边的空格去掉，类似php中的trim
    trim_str := strings.TrimSpace("       hello golang  i love you   ")
    fmt.Printf("last=%q", trim_str) //last="hello golang  i love you"
    
    
    //将字符串左右两边指定的字符串去掉
    str = strings.Trim("~#hello go lang%#~", "#~")  //第二个参数可以写多个字符
    fmt.Printf("last=%v" ,str)  //last=hello go lang%

    //将字符串左边的指定字符去掉|将字符串右边的指定字符去掉
    strings.TrimLeft()     |  strings.TrimRight()

    //判断字符串是否是指定字符串的开头
    b := strings.HasPrefix("http://192.168.0.1", "http")  //true
    fmt.Printf("bool=%b" ,b)  //bool= true
    //判断字符串止否是指定字符串的结尾
    strings.HasSuffix("test.png", "jpg")  //false

}

package main

import "fmt"
import "strings"

func main() {

    //Joins 组合
    s := []string{"abc", "def", "ghi", "lmn"}
    buf := strings.Join(s, "---")
    fmt.Println("buf = ", buf) // abc---def---ghi---lmn

    //重复次数拼接
    buf = strings.Repeat("go", 3)
    fmt.Println("buf = ", buf) //"gogogo"

    //去掉空格，把元素放入切片中
    s3 := strings.Fields("      are u ok?          ")
    //fmt.Println("s3 = ", s3)
    for i, data := range s3 {
        fmt.Println(i, ", ", data)
        //0 ,  are
        //1 ,  u
        //2 ,  ok?
    }
}