GO string 的学习

1.replace 

func Replace(s, old, new string, n int) string

s:原来的字符串    

old： 要被替换的久的字符串

new string：要替换旧字符串的新字符串

n:表示替换的次数

package main

import "strings"
import  "fmt"
 func  main() {
       str := "hello   world   abcd"
       result:= strings.Replace(str,"world","monday",1)
       fmt.Println(result);
 }

输出：

hello   monday   abcd

2.Count   

func Count

func Count(s, sep string) int

s：整个字符串

sep:里面的子字符串

返回： 返回字符串s中有几个不重复的sep子串。

package main

import "strings"
import  "fmt"
 func  main() {
       str := "hello   world   abcd"

       count:=strings.Count(str,"a");
       fmt.Println(count)
 }

输出：

  1

3.repeat  

func Repeat(s string, count int) string

string :字符串

count:重复几次 字符串

返回count个s串联的字符串。

package main

import "strings"
import  "fmt"
 func  main() {
 	  str := "hello   world   abcd"
 	  //result:= strings.Replace(str,"world","monday",1)
 	  //fmt.Println(result);
 	  //count:=strings.Count(str,"a");
 	  //fmt.Println(count)

 	  result:=strings.Repeat(str,2);
	 fmt.Println(result);
 }

　　输出：

hello   world   abcdhello   world   abcd

4.ToLower

func ToLower(s string) string

返回将所有字母都转为对应的小写版本的拷贝。

解释：将字符串全部转为小写

package main

import "strings"
import  "fmt"
 func  main() {
 	  str := "HELLO  WORLD"
 	  //result:= strings.Replace(str,"world","monday",1)
 	  //fmt.Println(result);
 	  //count:=strings.Count(str,"a");
 	  //fmt.Println(count)

 	//  result:=strings.Repeat(str,2);
	 //fmt.Println(result);

	 result:= strings.ToLower(str);
	 fmt.Println(result);
 }

　　输出：

hello  world

5. toupper

func ToUpper

func ToUpper(s string) string

返回将所有字母都转为对应的大写版本的拷贝。

解释：将字符串全部转为大写

package main

import "strings"
import  "fmt"
 func  main() {
       str := "hello world "
       //result:= strings.Replace(str,"world","monday",1)
       //fmt.Println(result);
       //count:=strings.Count(str,"a");
       //fmt.Println(count)

     //  result:=strings.Repeat(str,2);
     //fmt.Println(result);

     result:= strings.ToUpper(str)
     fmt.Println(result);
 }

输出：

HELLO WORLD 

6.strings.TrimSpace(str string)：  去掉字符串首尾空白字符

package main

import "strings"
import  "fmt"
 func  main() {
 	  str := "    hello world     "
 	  //result:= strings.Replace(str,"world","monday",1)
 	  //fmt.Println(result);
 	  //count:=strings.Count(str,"a");
 	  //fmt.Println(count)

 	//  result:=strings.Repeat(str,2);
	 //fmt.Println(result);

	 //result:= strings.ToUpper(str)
	 //fmt.Println(result);

	 result:=strings.TrimSpace(str);
	 fmt.Println(result);
 }

　　输出：

hello world

7.

strings.Trim(str string, cut string)：去掉字符串首尾cut字符

去掉指定的左右两边的字符串

package main

import "strings"
import  "fmt"
 func  main() {
 	  str := "11hello world11"
 	  //result:= strings.Replace(str,"world","monday",1)
 	  //fmt.Println(result);
 	  //count:=strings.Count(str,"a");
 	  //fmt.Println(count)

 	//  result:=strings.Repeat(str,2);
	 //fmt.Println(result);

	 //result:= strings.ToUpper(str)
	 //fmt.Println(result);

	 //result:=strings.TrimSpace(str);
	 //	 //fmt.Println(result);

	 result:=strings.Trim(str,"11");
	 fmt.Println(result);

 }

　　输出：

hello world

8. strings.TrimLeft(str string, cut string)：去掉字符串首cut字符

去掉左边的指定字符串

package main

import "strings"
import  "fmt"
 func  main() {
 	  str := "11hello world11"
 	  //result:= strings.Replace(str,"world","monday",1)
 	  //fmt.Println(result);
 	  //count:=strings.Count(str,"a");
 	  //fmt.Println(count)

 	//  result:=strings.Repeat(str,2);
	 //fmt.Println(result);

	 //result:= strings.ToUpper(str)
	 //fmt.Println(result);

	 //result:=strings.TrimSpace(str);
	 //	 //fmt.Println(result);

	 //result:=strings.Trim(str,"11");
	 //fmt.Println(result);
     result:=strings.TrimLeft(str,"11")
	 fmt.Println(result);
 }

　　输出：

hello world11

9.strings.TrimRight(str string, cut string)：去掉字符串首cut字符

去掉右边的指定字符串

package main

import (
	"fmt"
	"strings"
)

func  main() {
 	  str := "11hello world11"
 	  //result:= strings.Replace(str,"world","monday",1)
 	  //fmt.Println(result);
 	  //count:=strings.Count(str,"a");
 	  //fmt.Println(count)

 	//  result:=strings.Repeat(str,2);
	 //fmt.Println(result);

	 //result:= strings.ToUpper(str)
	 //fmt.Println(result);

	 //result:=strings.TrimSpace(str);
	 //	 //fmt.Println(result);

	 //result:=strings.Trim(str,"11");
	 //fmt.Println(result);
     //result:=strings.TrimLeft(str,"11")
	 //fmt.Println(result);
	 result:=strings.TrimRight(str,"11")
	 fmt.Println(result);
 }

　　输出：

11hello world

10. strings.Field(str string)：返回str空格分隔的所有子串的slice

将字符串切割成数组返回

package main

import (
"fmt"
"strings"
)

func  main() {
	str := "hello world  monday"
	//result:= strings.Replace(str,"world","monday",1)
	//fmt.Println(result);
	//count:=strings.Count(str,"a");
	//fmt.Println(count)

	//  result:=strings.Repeat(str,2);
	//fmt.Println(result);

	//result:= strings.ToUpper(str)
	//fmt.Println(result);

	//result:=strings.TrimSpace(str);
	//	 //fmt.Println(result);

	//result:=strings.Trim(str,"11");
	//fmt.Println(result);
	//result:=strings.TrimLeft(str,"11")
	//fmt.Println(result);
	//result:=strings.TrimRight(str,"11")
	//fmt.Println(result);

	splitResult:= strings.Fields(str)
    for  i:=0;i<len(splitResult);i++ {
		fmt.Println(splitResult[i]);
	}
}

　　输出：

hello
world
monday

11.strings.Split(str string, split string)：返回str split分隔的所有子串的slice

将字符串按照特定的方式分割成子串

按照某个子字符进行切割

package main

import (
"fmt"
"strings"
)

func  main() {
	str := "hello world monday"
	//result:= strings.Replace(str,"world","monday",1)
	//fmt.Println(result);
	//count:=strings.Count(str,"a");
	//fmt.Println(count)

	//  result:=strings.Repeat(str,2);
	//fmt.Println(result);

	//result:= strings.ToUpper(str)
	//fmt.Println(result);

	//result:=strings.TrimSpace(str);
	//	 //fmt.Println(result);

	//result:=strings.Trim(str,"11");
	//fmt.Println(result);
	//result:=strings.TrimLeft(str,"11")
	//fmt.Println(result);
	//result:=strings.TrimRight(str,"11")
	//fmt.Println(result);

	//splitResult:= strings.Fields(str)
    //for  i:=0;i<len(splitResult);i++ {
	//	fmt.Println(splitResult[i]);
	//}

	splitResult:= strings.Split(str,"o")
	for  i:=0;i<len(splitResult);i++ {
		fmt.Println(splitResult[i]);
	}
}

　　输出：

hell
w
rld m
nday

12.strings.Join(s1 []string, sep string)：用sep把s1中的所有元素链接起来

用sep把s1中的所有元素链接起来

package main

import (
"fmt"
"strings"
)

func  main() {
	str := "hello world monday"
	//result:= strings.Replace(str,"world","monday",1)
	//fmt.Println(result);
	//count:=strings.Count(str,"a");
	//fmt.Println(count)

	//  result:=strings.Repeat(str,2);
	//fmt.Println(result);

	//result:= strings.ToUpper(str)
	//fmt.Println(result);

	//result:=strings.TrimSpace(str);
	//	 //fmt.Println(result);

	//result:=strings.Trim(str,"11");
	//fmt.Println(result);
	//result:=strings.TrimLeft(str,"11")
	//fmt.Println(result);
	//result:=strings.TrimRight(str,"11")
	//fmt.Println(result);

	//splitResult:= strings.Fields(str)
    //for  i:=0;i<len(splitResult);i++ {
	//	fmt.Println(splitResult[i]);
	//}

	splitResult:= strings.Split(str,"o")
	//for  i:=0;i<len(splitResult);i++ {
	//	fmt.Println(splitResult[i]);
	//}
	str2:=strings.Join(splitResult,"o")
	fmt.Println(str2);



}

　　输出：hello world monday