Learning Golang Language (4): Type--string

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Follow the "code technique" to learn Golang language, lazy for many days, today continue to explain the type of Golang. Today, the string is explained.

Learning Golang Language (1): Hello World

Learning Golang Language (2): Variables

Learning Golang Language (3): Type--Boolean and numeric types

Learning Golang Language (4): Type--string

Learning Golang Language (5): Type--array

Learning Golang Language (6): Type--slice

Numeric type

Add a place not indicated in the previous section:

Golang also defines the types of three dependent systems : int, unint, and UIntPtr. Because the number of bits used to represent these types is different on 32-bit systems and 64-bit systems.

String

Another important built-in type in Golang is string.

A string is a sequence of characters concatenated with fixed-length characters. The string of Go is connected by a single byte. That is, the traditional string is made up of characters, and go's string is different, it is composed of bytes.

The byte of the Go language uses UTF-8 encoding to identify Unicode text.
The representation of a string is simple, and is created using double quotation marks ("") or anti-quotation marks ("'). For example: "Hello World" or ' Hello World '.

The difference between the two:

The escape character between the double quotes is escaped, and the characters between the anti-quotes remain unchanged. For example:

Output:

If single quotation marks (') are used to denote one character (UTF-8 encoding)----This is not a string in the go language.

Once the string has been assigned, the string cannot be modified: The string is immutable in go. Some operations are illegal on go.

var s = "Hello World"

S[0] = ' C ' <-----Modify the first character to ' C ', which returns the wrong one.

This needs to be done in go:

1. Convert s to rune array, 2, modify the first element of the array, 3, create a new string s2;4, print output.

Multi-line string

Since the go language automatically adds semicolons after each line, it is important to note that when using multiple lines of string:

S: = "Starting part"

+ "Ending part"

will be automatically converted to:

S: = "starting part";

+ "Ending part";

This is wrong and should be written as:

S: = "Starting part" + "ending part"

So go does not insert semicolons in the wrong place, another way is to use the back quotation marks (') as the original string symbol:

S: = ' starting part

Ending part '

s also contains a line break. Because the characters in the middle of the anti-quote will remain unchanged.

String conversions

You can use a string (char) to convert a character to a string that contains a single character.

Package for string processing

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String Package

including string segmentation, substitution, merging and other processing;

StrConv Bag

Provides a number of conversion functions that can be used between strings and other types of data.

Utf-8 Bag

Used primarily to query and manipulate UTF-8 encoded strings or character slices.

Unicode Package

Provides some functions to check whether Unicode code points conform to the main criteria.

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Rune

Rune is the alias of Int32. Encode with UTF-8. When does this type work? For example, when you need to traverse a character string, you can mix each byte. To get the actual characters, you need to use the Rune type.

Output Result:

6

2 [20320 22909]

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