How to use string processing in Go?

Go, as a powerful programming language, provides many string processing functions and methods. In order for us to better master this knowledge, this article will introduce the string type and basic string processing functions in Go, including string creation, concatenation, cutting, comparison and search.

1. String type

In Go, the string type is defined as a read-only character sequence, type string. A string value is composed of a sequence of characters enclosed by a pair of double quotes, for example:

str := "Hello, world!"

The string is read-only, and we cannot modify certain characters in the string. You can change the value of a string by reassigning it, such as:

str := "Hello, world!"
str = "Hello, Golang!"

2. Creation of string

There are many ways to create a string, as follows Here are some of them:

• Direct declaration and assignment

For example:

str := "Hello, world!"

This method is the simplest and most commonly used method. It should be noted that in Go, special characters in double-quoted strings need to be represented by escape characters, for example:

str := "This is a "quoted" string."

• Use character array to create

Creating a string through a character array is also a feasible way, for example:

str := []byte{'H', 'e', 'l', 'l', 'o', ',', ' ', 'w', 'o', 'r', 'l', 'd', '!'}
str_1 := string(str)

The above code creates a byte type character array and converts it to a string type. It should be noted that in Go, strings and character arrays are two different types.

• Create using fmt.Sprintf

We can use the fmt.Sprintf function to create a string, similar to the sprintf function in C language. For example:

str := fmt.Sprintf("The value of x is %d", x)

3. Concatenation of strings

Concatenation of strings can use the " " operator, for example:

str1 := "Hello"
str2 := ", world!"
result := str1 + str2

or use fmt.Sprintf Function, for example:

str1 := "Hello"
str2 := ", world!"
result := fmt.Sprintf("%s%s", str1, str2)

It should be noted that the concatenation of strings will produce new strings. When there are many operations, a large number of temporary strings will be generated, which may affect the performance of the program.

4. String cutting

String cutting can use the Split function in the strings package, for example:

str := "apple,orange,peach"
slice := strings.Split(str, ",")

The above code is separated by commas symbol to cut the string str into a slice.

5. Comparison of strings

Comparison of strings can use the "==" operator or the Equal function in the strings package, for example:

str1 := "Hello"
str2 := "world"
equal := (str1 == str2)
equal_1 := strings.EqualFold(str1, str2)

The above code uses the "==" operator and the EqualFold function in the strings package to compare the equality of two strings.

It should be noted that in Go, string comparison is case-sensitive. If you need to be case-insensitive, you can use the EqualFold function in the strings package.

6. String search

Go provides multiple functions to search for strings, including:

• strings.Contains: Judgment Whether a string contains another string.

str := "Hello, world!"
contains := strings.Contains(str, "world") // 返回true

• strings.Index: Find the first occurrence of a string in another string.

str := "Hello, world!"
index := strings.Index(str, "world") // 返回7

• strings.LastIndex: Find the last occurrence of a string in another string.

str := "Hello, world!"
index := strings.LastIndex(str, "o") // 返回8

• strings.HasPrefix: Determine whether a string starts with another string.

str := "Hello, world!"
hasPrefix := strings.HasPrefix(str, "Hello") // 返回true

• strings.HasSuffix: Determine whether a string ends with another string.

str := "Hello, world!"
hasSuffix := strings.HasSuffix(str, "world!") // 返回true

Summary

This article introduces the basic string processing functions and methods. In actual development, we will use more string operations, such as replacement, size Write conversions, format output, and more. Readers who need in-depth understanding can refer to official documentation and sample code for further learning.

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