字符串是不可变值类型,内部用指针指向 UTF-8 字节数组。
• 默认值是空字符串 ""。• 用索引号访问某字节,如 s[i]。• 不能用序号获取字节元素指针,&s[i] 非法。 • 不可变类型,无法修改字节数组。• 字节数组尾部不包含 NULL。
使用索引号访问字符 (byte)。
package mainfunc main() { s := "abc" println(s[0] == '\x61', s[1] == 'b', s[2] == 0x63)}
输出结果:
true true true
使用 " ` " 定义不做转义处理的原始字符串,支持跨行。
package mainfunc main() { s := `ab\r\n\x00c` println(s)}
输出结果:
ab\r\n\x00c
连接跨行字符串时,"+" 必须在上一行末尾,否则导致编译错误。
package mainimport ( "fmt")func main() { s := "Hello, " + "World!" // s2 := "Hello, " // +"World!" //./main.go:11:2: invalid operation: + untyped string fmt.Println(s)}
支持用两个索引号 ([]) 返回子串。 串依然指向原字节数组,仅修改了指针和 度属性。
package mainimport ( "fmt")func main() { s := "Hello, World!" s1 := s[:5] // Hello s2 := s[7:] // World! s3 := s[1:5] // ello fmt.Println(s, s1, s2, s3)}
输出结果:
Hello, World! Hello World! ello
单引号字符常量表示 Unicode Code Point, 持 \uFFFF、\U7FFFFFFF、\xFF 格式。
对应 rune 类型,UCS-4。
package mainimport ( "fmt")func main() { fmt.Printf("%T\n", 'a') var c1, c2 rune = '\u6211', '们' println(c1 == '我', string(c2) == "\xe4\xbb\xac")}
输出结果:
int32 // rune 是 int32 的别名 true true
要修改字符串,可先将其转换成 []rune 或 []byte,完成后再转换为 string。无论哪种转换,都会重新分配内存,并复制字节数组。
package mainfunc main() { s := "abcd" bs := []byte(s) bs[1] = 'B' println(string(bs)) u := "电脑" us := []rune(u) us[1] = '话' println(string(us))}
输出结果:
aBcd电话
for 循环遍历字符串时,也有 byte 和 rune 两种方式。
package mainimport ( "fmt")func main() { s := "abc汉字" for i := 0; i < len(s); i++ { // byte fmt.Printf("%c,", s[i]) } fmt.Println() for _, r := range s { // rune fmt.Printf("%c,", r) } fmt.Println()}
输出结果:
a,b,c,æ,±,�,å,,�,a,b,c,汉,字,
string的底层布局

字符串处理:
判断是不是以某个字符串开头
package mainimport ( "fmt" "strings")func main() { str := "hello world" res0 := strings.HasPrefix(str, "http://") res1 := strings.HasPrefix(str, "hello") fmt.Printf("res0 is %v\n", res0) fmt.Printf("res1 is %v\n", res1)}
输出结果:
res0 is falseres1 is true
判断是不是以某个字符串结尾
package mainimport ( "fmt" "strings")func main() { str := "hello world" res0 := strings.HasSuffix(str, "http://") res1 := strings.HasSuffix(str, "world") fmt.Printf("res0 is %v\n", res0) fmt.Printf("res1 is %v\n", res1)}
输出结果:
res0 is falseres1 is true
判断str在s中首次出现的位置,如果没有返回-1
package mainimport ( "fmt" "strings")func main() { str := "hello world" res0 := strings.Index(str, "o") res1 := strings.Index(str, "i") fmt.Printf("res0 is %v\n", res0) fmt.Printf("res1 is %v\n", res1)}
输出结果:
res0 is 4res1 is -1
判断str在s中最后一次出现的位置,如果没有返回-1
package mainimport ( "fmt" "strings")func main() { str := "hello world" res0 := strings.LastIndex(str, "o") res1 := strings.LastIndex(str, "i") fmt.Printf("res0 is %v\n", res0) fmt.Printf("res1 is %v\n", res1)}
输出结果:
res0 is 7res1 is -1
字符串替换
package mainimport ( "fmt" "strings")func main() { str := "hello world world" res0 := strings.Replace(str, "world", "golang", 2) res1 := strings.Replace(str, "world", "golang", 1) //trings.Replace("原字符串", "被替换的内容", "替换的内容", 替换次数) fmt.Printf("res0 is %v\n", res0) fmt.Printf("res1 is %v\n", res1)}
输出结果:
res0 is hello golang golangres1 is hello golang world
求str含s的次数
package mainimport ( "fmt" "strings")func main() { str := "hello world world" countTime0 := strings.Count(str, "o") countTime1 := strings.Count(str, "i") fmt.Printf("countTime0 is %v\n", countTime0) fmt.Printf("countTime1 is %v\n", countTime1)}
输出结果:
countTime0 is 3countTime1 is 0
重复 n 次 str
package mainimport ( "fmt" "strings")func main() { str := "hello world " res0 := strings.Repeat(str, 0) res1 := strings.Repeat(str, 1) res2 := strings.Repeat(str, 2) // strings.Repeat("原字符串", 重复次数) fmt.Printf("res0 is %v\n", res0) fmt.Printf("res1 is %v\n", res1) fmt.Printf("res2 is %v\n", res2)}
输出结果:
res0 is res1 is hello world res2 is hello world hello world
str 转为大写
package mainimport ( "fmt" "strings")func main() { str := "hello world " res := strings.ToUpper(str) fmt.Printf("res is %v\n", res)}
输出结果:
res is HELLO WORLD
str 转为小写
package mainimport ( "fmt" "strings")func main() { str := "HELLO WORLD " res := strings.ToLower(str) fmt.Printf("res is %v\n", res)}
输出结果:
res is hello world
去掉 str 首尾的空格
package mainimport ( "fmt" "strings")func main() { str := " hello world " res := strings.TrimSpace(str) fmt.Printf("res is %v\n", res)}
去掉字符串首尾指定的字符
package mainimport ( "fmt" "strings")func main() { str := "hi , hello world , hi" res := strings.Trim(str, "hi") fmt.Printf("res is %v\n", res)}
输出结果:
res is , hello world ,
去掉字符串首指定的字符
package mainimport ( "fmt" "strings")func main() { str := "hi , hello world , hi" res := strings.TrimLeft(str, "hi") fmt.Printf("res is %v\n", res)}
输出结果:
res is , hello world , hi
去掉字符串尾指定的字符
package mainimport ( "fmt" "strings")func main() { str := "hi , hello world , hi" res := strings.TrimRight(str, "hi") fmt.Printf("res is %v\n", res)}
输出结果:
res is hi , hello world ,
返回str空格分隔的所有子串的slice,
package mainimport ( "fmt" "strings")func main() { str := "hello world ,hello golang" res := strings.Fields(str) fmt.Printf("res is %v\n", res)}
输出结果:
res is [hello world ,hello golang]
返回str 指定字符分隔的所有子串的slice
package mainimport ( "fmt" "strings")func main() { str := "hello world ,hello golang" res := strings.Split(str, "o") fmt.Printf("res is %v\n", res)}
输出结果:
res is [hell w rld ,hell g lang]
用指定字符将 string 类型的 slice 中所有元素链接成一个字符串
package mainimport ( "fmt" "strings")func main() { str := []string{"hello", "world", "hello", "golang"} res := strings.Join(str, "++") fmt.Printf("res is %v\n", res) /* num := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 0} res1 := strings.Join(num, "++") // cannot use num (type []int) as type []string in argument to strings.Join fmt.Println(res1) */}
输出结果:
res is hello++world++hello++golang
文章来源:智云一二三科技
文章标题:[GO语言]Golang String字符串的操作大全
文章地址:https://www.zhihuclub.com/282.shtml