Master the common applications of Golang pointers and improve your code efficiency

Common uses of Golang pointers to help you write efficient code

In Golang, a pointer is a special data type that stores the memory address of a variable . By using pointers, we can directly access and modify data in memory, which is very useful in writing efficient code. This article will introduce the common usage of pointers in Golang and provide specific code examples.

1. Address and value of variables

In Golang, you can use the address operator & to obtain the address of a variable, and the dereference operator * to obtain it. The value corresponding to this address. The following is a simple example:

package main

import "fmt"

func main() {
     var num int = 10
     fmt.Printf("num的地址：%p
", &num)
     fmt.Printf("num的值：%d
", *(&num))
}

The output result is as follows:

num的地址：0xc0000...
num的值：10

2. The pointer is used as a function parameter

When the pointer is used as a function parameter, the original value can be modified The value of the variable. This is very useful in scenarios where variables need to be modified inside a function. The following is an example:

package main

import "fmt"

func changeValue(num *int) {
     *num = 20
}

func main() {
     var num int = 10
     fmt.Printf("修改前的值：%d
", num)
     changeValue(&num)
     fmt.Printf("修改后的值：%d
", num)
}

The output result is as follows:

修改前的值：10
修改后的值：20

3. Pointer as function return value

Pointer can also be used as function return value, use Creates a new variable inside the function and returns its address to the caller. This can avoid large amounts of data copying during function calls and improve code execution efficiency. The following is an example:

package main

import "fmt"

func createPointer() *int {
     num := 10
     return &num
}

func main() {
     pointer := createPointer()
     fmt.Printf("指针的值：%d
", *pointer)
}

The output is as follows:

指针的值：10

4. Use pointers to access the fields of the structure

In Golang, you can use pointers to Access the fields of the structure, which can avoid copying the entire structure and improve the execution efficiency of the program. The following is an example:

package main

import "fmt"

type Person struct {
     Name string
     Age  int
}

func main() {
     p := &Person{Name: "Alice", Age: 20}
     fmt.Printf("姓名：%s
", (*p).Name)
     fmt.Printf("年龄：%d
", (*p).Age)
}

The output is as follows:

姓名：Alice
年龄：20

5. Use the new keyword to create a pointer

In Golang, you can use the new keyword to create a zero value of the specified type and return a pointer to it. This is very convenient in scenarios where new variables need to be created without initialization. The following is an example:

package main

import "fmt"

func main() {
     p := new(Person)
     fmt.Printf("姓名：%s
", p.Name)
     fmt.Printf("年龄：%d
", p.Age)
}

type Person struct {
     Name string
     Age  int
}

The output is as follows:

姓名：
年龄：0

By understanding these common uses of Golang pointers, we can write efficient code more flexibly. However, care needs to be taken when using pointers to avoid problems such as null pointer errors and memory leaks. Therefore, careful consideration and caution are required when using pointers. I hope this article will help you understand the usage of Golang pointers and can play a greater role in actual projects.

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