Detailed explanation of how to use Golang arrays

In recent years, Golang (Go language) has been growing in popularity among developers. Golang not only has the efficiency and reliability of C language, but also has the simplicity and ease of learning of Python language. Among them, array is an important data type in Golang. In this article, we will focus on the usage of Golang array.

1. Definition of array

Declaring an array in Golang requires specifying the type and length of the array. The syntax is as follows:

var arr [长度]类型

For example, declare an array with a length of 5 Array of int type:

var arr [5]int

At this time, Golang will allocate space for us and initialize it according to the default value of the type (the default value of int type is 0), as follows:

[0 0 0 0 0]

Also Use an initializer to assign an initial value to the array, for example:

var arr = [5]int{1, 2, 3, 4, 5}

or it can be abbreviated as:

arr := [5]int{1, 2, 3, 4, 5}

Both of the above methods can create an array with a length of 5 and assign the initial value to 1 ,2,3,4,5.

If there is no fixed limit on the length of the array, you can use slicing.

2. Basic operations of arrays

1. Get the length of the array

In Golang, you can use the len() function to get the length of the array, for example:

arr := [5]int{1, 2, 3, 4, 5}
length := len(arr)
fmt.Println(length) //输出5

2. Access array elements

In Golang, you can use array subscripts to access array elements, and array subscripts start counting from 0. For example:

arr := [5]int{1, 2, 3, 4, 5}
fmt.Println(arr[0]) //输出1
fmt.Println(arr[4]) //输出5

3. Modify array elements

In Golang, you can modify the value of array elements by subscripting, for example:

arr := [5]int{1, 2, 3, 4, 5}
arr[0] = 100
fmt.Println(arr) //输出[100 2 3 4 5]

3. Multi-dimensional array

In Golang, you can also use multi-dimensional arrays. A multidimensional array is an array in which one element is an array. Similar to a one-dimensional array, the syntax for declaring a two-dimensional array is as follows:

var arr [长度1][长度2]类型

For example:

var arr [4][2]int

The above operation creates a two-dimensional array with 4 rows and 2 columns.

The access and modification of multi-dimensional arrays are also similar to one-dimensional arrays, using subscripts, for example:

arr := [4][2]int{{1, 2}, {3, 4}, {5, 6}, {7, 8}}
fmt.Println(arr[0][0]) //输出1
fmt.Println(arr[1][1]) //输出4 
arr[2][1] = 10
fmt.Println(arr) //输出[[1 2] [3 4] [5 10] [7 8]]

4. Array traversal

In Golang, you can use for loop easily iterates through array elements. For example:

arr := [5]int{1, 2, 3, 4, 5}
for i := 0; i < len(arr); i++ {
    fmt.Println(arr[i])
}

Or you can use the range keyword to traverse:

arr := [5]int{1, 2, 3, 4, 5}
for index, value := range arr {
    fmt.Printf("arr[%d] = %d \n", index, value)
}

Both of the above two methods can traverse the elements in the output array.

5. Arrays as parameters

In Golang, arrays can also be used as parameters of functions. For example:

func sum(arr [5]int) int {
    var sum int
    for _, value := range arr {
        sum += value
    }
    return sum
}

func main() {
    arr := [5]int{1, 2, 3, 4, 5}
    fmt.Println(sum(arr))
}

In the above code, the sum() function receives an int type array with a length of 5 as a parameter and returns the sum of this array.

6. Convert slice to array

Slice is another very important data type in Golang and can be dynamically expanded. If you need to convert Slice into an array, you can use the copy() function, for example:

slice := []int{1, 2, 3, 4, 5}
var arr [5]int
copy(arr[:], slice)
fmt.Println(arr) //输出[1 2 3 4 5]

7. Summary

This article mainly introduces the basic knowledge of Golang arrays, including the definition and basic operations of arrays , multidimensional arrays, traversing, arrays as parameters and converting slices to arrays, etc. If you are a Golang developer, learning and mastering the usage of arrays will help improve your programming skills and development efficiency.

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