go 字符串方法

package main

import (

"fmt"

"strconv"

"strings"

)

func main() {

//1.strings.HasPrefix(s string, prefix string) bool：判断字符串s是否以prefix开头

fmt.Println(strings.HasPrefix("hello world", "he")) //true

//2.strings.HasSuffix(s string, suffix string) bool：判断字符串s是否以suffix结尾

fmt.Println(strings.HasSuffix("hello world", "ll")) //false

//3.strings.Index(s string, str string) int：判断str在s中首次出现的位置，如果没有出现，则返回-1

fmt.Println(strings.Index("hello world", "he")) //0

//4.strings.LastIndex(s string, str string) int：判断str在s中最后出现的位置，如果没有出现，则返回-1

fmt.Println(strings.LastIndex("hello world", "or")) //7

//5.strings.Replace(str string, old string, new string, n int)：字符串替换

fmt.Println(strings.Replace("he12he wohe12", "he", "ww", 2)) //ww12ww wohe12

//6.strings.Count(str string, substr string)int：字符串计数

fmt.Println(strings.Count("hehehe123he123eheh", "he")) //5

//7.strings.Repeat(str string, count int)string：重复count次str

fmt.Println(strings.Repeat("hello", 5)) //hellohellohellohellohello

//8.strings.ToLower(str string)string：转为小写

fmt.Println(strings.ToLower("HELLO")) //hello

//9.strings.ToUpper(str string)string：转为大写

fmt.Println(strings.ToUpper("hello")) //HELLO

//10.strings.TrimSpace(str string)：去掉字符串首尾空白字符

fmt.Println(strings.TrimSpace(" hello world ")) //hello world

//11.strings.Trim(str string, cut string)：去掉字符串首尾cut字符

fmt.Println(strings.Trim("abchelloba", "ab")) //chello

//12.strings.TrimLeft(str string, cut string)：去掉字符串首cut字符

fmt.Println(strings.TrimLeft("abchelloba", "ab")) //chelloba

//13.strings.TrimRight(str string, cut string)：去掉字符串首cut字符

fmt.Println(strings.TrimRight("abchelloba", "ab")) //abchello

//14.strings.Fields(str string)：返回str空格分隔的所有子串的slice

fmt.Println(strings.Fields("hello world abc")) //[hello world abc]

//15.strings.Split(str string, split string)：返回str split分隔的所有子串的slice

fmt.Println(strings.Split("abca12a34a", "a")) //[ bc 12 34 ]

//16.strings.Join(s1 []string, sep string)：用sep把s1中的所有元素链接起来

fmt.Println(strings.Join([]string{"123", "abc", "456"}, "xx")) //123xxabcxx456

//17.strconv.Itoa(i int)：把一个整数i转成字符串

fmt.Println(strconv.Itoa(3)) //"3"

//18.strconv.Atoi(str string)(int, error)：把一个字符串转成整数

fmt.Println(strconv.Atoi("38")) //38 nil