十五、Go 语言 – 字符串

Strings, which are widely used in Go programming, are a readonly slice of bytes. In the Go programming language, strings are slices . The Go platform provides various libraries to manipulate strings. – unicode – regexp – strings

Creating Strings

Themost direct way to create a string is to write −

var greeting = "Hello world!"

Whenever it encounters a string literal in your code, the compiler creates a string object with its value in this case, “Hello world!’.

Astring literal holds a valid UTF-8 sequences called runes. A String holds arbitrary bytes.

/**
 * file: main.go
 * author: DDKK.COM 弟弟快看，程序员编程资料站(ddkk.com)
 * Copyright © 2015-2065 ddkk.com. All rights reserved.
 */
package main
import "fmt"
func main() {
   var greeting =  "Hello world!"
   fmt.Printf("normal string: ")
   fmt.Printf("%s", greeting)
   fmt.Printf("\n")
   fmt.Printf("hex bytes: ")
   for i := 0; i < len(greeting); i++ {
       fmt.Printf("%x ", greeting[i])
   }
   fmt.Printf("\n")
   const sampleText = "\xbd\xb2\x3d\xbc\x20\xe2\x8c\x98" 
   /*q flag escapes unprintable characters, with + flag it escapses non-ascii 
   characters as well to make output unambigous  
   */
   fmt.Printf("quoted string: ")
   fmt.Printf("%+q", sampleText)
   fmt.Printf("\n")  

This would produce the following result −

normal string: Hello world!
hex bytes: 48 65 6c 6c 6f 20 77 6f 72 6c 64 21 
quoted string: "\xbd\xb2=\xbc \u2318"

Note − The string literal is immutable, so that once it is created a string literal cannot be changed.

String Length

len(str) method returns the number of bytes contained in the string literal.

/**
 * file: main.go
 * author: DDKK.COM 弟弟快看，程序员编程资料站(ddkk.com)
 * Copyright © 2015-2065 ddkk.com. All rights reserved.
 */
package main
import "fmt"
func main() {
   var greeting =  "Hello world!"
   fmt.Printf("String Length is: ")
   fmt.Println(len(greeting))  

This would produce the following result −

String Length is : 12

Concatenating Strings

Thestrings package includes a method join for concatenating multiple strings −

strings.Join(sample, " ")

Join concatenates the elements of an array to create a single string. Second parameter is seperator which is placed between element of the array.

Letus look at the following example −

/**
 * file: main.go
 * author: DDKK.COM 弟弟快看，程序员编程资料站(ddkk.com)
 * Copyright © 2015-2065 ddkk.com. All rights reserved.
 */
package main
import ("fmt" "math" )"fmt" "strings")
func main() {
   greetings :=  []string{"Hello","world!"}   
   fmt.Println(strings.Join(greetings, " "))

This would produce the following result −

Hello world!