Golang function pointer array and array pointer application skills

With the continuous development of the Golang language, function pointer arrays and array pointers have also become an important part of Golang programming. In this article, we will discuss the application skills of pointer arrays and array pointers in Golang functions, and provide you with some practical sample codes and related explanations.

Basic concepts of Golang pointer array

First of all, let us first understand the Golang pointer array. An array of pointers is a data type that is an array consisting of multiple pointers pointing to different variables or objects. You can use the following code to declare a pointer array:

var ptrArr [4]*int

This code will declare a pointer array of length 4, where each element is a pointer to int type. Of course, you can also set the length of the array to any value you want.

In Golang, we can add elements to a pointer array in the following way:

var p1 = new(int)
var p2 = new(int)
var p3 = new(int)
var p4 = new(int)
ptrArr := [4]*int{p1, p2, p3, p4}

The pointer variable created through the new function will allocate a memory address and return a pointer to that address. . Therefore, the above code will add four elements to the pointer array, each element pointing to a variable of type int.

Application of pointer array

Pointer array is very useful in Golang programming, and it can be used in many different situations. Here are a few practical use cases:

1. Use a pointer array to assign multiple variables

Suppose you need to set multiple variables to the same value, You can use an array of pointers for this purpose. The following code shows how to use an array of pointers to set multiple variables of type int:

var a, b, c, d int
ptrArr := [4]*int{&a, &b, &c, &d}

for _, p := range ptrArr{
  *p = 8
}

fmt.Println(a, b, c, d) //将会输出 "8 8 8 8"

In this example, we first declare four variables of type int, and then create an array of pointers with each element They are all pointers to these four variables. Next, we use a for loop to iterate through this array of pointers and set the value pointed to by each pointer to 8.

2. Use pointer arrays to assign values ​​to variables of different types

The difference from the previous example is that in this example, we need to assign two variables of different types. Set to the same value. The following code shows how to use an array of pointers to set a variable of type string and a variable of type int:

var i int
var j string
ptrArr := [2]interface{}{&i, &j}

for _, p := range ptrArr{
  switch t := p.(type) {
   case *int:
     *t = 5
   case *string:
     *t = "Golang"
  }
}

fmt.Println(i, j) //将会输出 "5 Golang"

In this example, we use a pointer array of length 2, one of which is the pointer to A pointer to an int type variable, and the other is a pointer to a string type variable. We iterate through this array of pointers through a for loop and a switch statement, and set the value pointed by each pointer to the corresponding value.

Basic concepts of Golang array pointers

Next, let’s learn about Golang array pointers. An array pointer is a pointer to an array. You can use the following code to declare an array pointer:

var arrPtr *[4]int

In this example, we declare a pointer to an array of type int. This pointer can be used to manipulate the entire array.

Using array pointers

In Golang programming, array pointers can be used for a variety of different tasks. Here are some examples of using array pointers:

1. Passing arrays to functions as pointers

In Golang, arrays and slices are both value types, which means that when When you pass an array to a function, the function creates a copy of the array. If you want to modify the array passed to the function, you need to use an array pointer. The following code shows how to pass an array to a function using an array pointer:

func modifyArray(arr *[4]int) {
  arr[0] = 5
  arr[2] = 7
}

var arr [4]int
arrPtr := &arr
modifyArray(arrPtr)
fmt.Println(arr) //将会输出 "[5 0 7 0]"

In this example, we first declare an array and an array pointer. Next, we pass the array pointer to a function called modifyArray, which modifies the array passed to it. In the function modifyArray, we can access the array outside the function through the array pointer and modify it.

2. Using array pointers as replacements for arrays

In some scenarios, array pointers can replace arrays to achieve the same purpose. The following code shows how to use an array pointer to operate an array:

arrPtr := new([4]int)
for i := 0; i < 4; i++ {
  arrPtr[i] = i + 1
}

for _, v := range arrPtr {
  fmt.Println(v)  //将会输出 "1 2 3 4"
}

In this example, we use the new function to allocate a new array and point it to an array pointer. We can access each element in the array through this pointer, just like accessing an ordinary array.

Conclusion

In this article, we have deeply discussed the pointer array of Golang functions and the application skills of array pointers, and also provided you with some practical sample codes and related explanations.

Pointer arrays and array pointers are very important tools in Golang programming, and they can be used in many different scenarios. As long as you understand their basic concepts and usage methods, you will be more comfortable in Golang programming.

The above is the detailed content of Golang function pointer array and array pointer application skills. For more information, please follow other related articles on the PHP Chinese website!