golang field type conversion

Golang field type conversion

In Golang, the type of variables is relatively strict, which is one of the reasons why the Golang language design is excellent. But in actual programming scenarios, we will encounter situations where conversion between different types of values ​​is required. Therefore, it is important to understand type conversion in Golang.

In Golang, type conversion refers to converting a variable from one type to another type. Let's take a look at how to perform type conversion in Golang.

1. Same type conversion

First, let’s look at the same type conversion. When we need to convert values ​​of the same type into different expressions, we can use cast to achieve this. For example:

var a int = 65
var b string = string(a)

The above code converts the value of variable a to an ASCII value of one character Assign a value to variable b. In Golang, basic data types support casts. However, it should be noted that during type conversion, it is necessary to ensure that the actual types of variables before and after conversion are compatible.

2. Different type conversion

When we need to convert values ​​of different types into target types, we need to use forced type conversion. Since Golang is a statically typed language, when performing forced type conversion, you need to ensure that the converted type is compatible with the variable storage content, otherwise exceptions or unexpected results will occur. For example:

var a float32 = 3.14
var b int = int(a)

In the above code, we convert a floating point type variable a to an integer type, and Assign the result to an integer variable b. Since the precision of floating point types is higher than that of integer types, conversion of floating point types may cause data loss and needs to be used with caution.

There are also some data type conversions that need attention. For example, since the default conversion from string to integer type is not supported in Golang, you need to use the strconv package when converting a string type number to an integer type. For example:

import "strconv"

func main() {
str := "1234"
num, _ := strconv.Atoi(str)
fmt .Printf("Type: %T, Value: %d", num, num)
}

In the above code, we need to use the Atoi method in the strconv package to convert the string type number For integer type.

In addition to the strconv package, there are also JSON, protobuf and other libraries specifically used for data serialization and deserialization, which can realize conversion between different data types.

3. Interface type conversion

Golang is a strongly typed language, but in some cases, we need to establish a common interface between different types. At this time, we can use interface type conversion. For example:

type MyInterface interface {
Method1()
Method2()
}

type MyStruct struct {
name string
}

func (m *MyStruct) Method1() {
fmt.Println("Method1 called")
}

func (m *MyStruct) Method2() {
fmt. Println("Method2 called")
}

func main() {
var i MyInterface
i = &MyStruct{"MyStruct"}
m := i.(*MyStruct )
fmt.Printf("Value: %#v", m)
}

In the above code, we define a MyInterface interface, which defines two methods. Then a structure MyStruct that implements the MyInterface interface is defined, and the interface type variable i is used for assignment in the main function. Finally, we use interface type conversion to convert the interface type variable i to the MyStruct type and print the value of the variable m.

It should be noted that when performing interface type conversion, you must ensure that the source type implements all methods of the target interface, otherwise a runtime exception will occur.

Summary

Type conversion is an important topic in Golang programming, which can help us quickly and accurately complete data type conversion when we need to convert different data types. However, it should be noted that when performing data type conversion, the compatibility of types before and after conversion must be ensured, otherwise unexpected results will result.

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