C arrays and similar array, is a unique slice sliced
Array
- Golang array as a value type is defined as follows:
var intArray [3] int // define an array of integers, comprising three elements, wherein the subscript 0,1,2
var flArray [. 3] // define a float64 float64 array, comprising three elements, the initial values are is 0
var intArray [. 3] = int [. 3] int {10,20,30} // define an array of integers, comprising three elements and assigns
var intArray [3] string = [ 3] string { "Kobe", " Durant "," James "} // definition of a string array and assign
var intArray [. 3] = string [. 3] 0 {string:" Kobe ": 2:" Durant ":. 1:" James "} // definition of a string array and assigned subscripts indicate by what corresponds to a value
intArray var [. 3] int
intArray [0] = 10
intArray [. 1] = 20 is
intArray [2] // = 30 or so assigned
var arr [] int // !!! this is not an array, a slice Slice
var intArray1 = [ ...] int {10,20,30} // let the system recognize it, with function parameters args ... Like, three essential points
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Open address in memory array contiguous space together, each element of the specific memory space of the data determined, the address of an array is the array a [0] is
& intArray [0] == & intArray -
Array traversal: for-range structure traversal
for _, value: = range intArray {...} // traverse such an array each element -
Array is a combination of a plurality of the same data type, length once the declaration is fixed and can not dynamically change
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Array [] xx, xx is a value type may be also be a reference type, but attention must be consistent with the data types, data types can not be different from the composition of the array, i.e., can not be mixed
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The default value of the array: int 0; string ""; bool false
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To use an array of:
(1) declare an array variable and open up contiguous memory space
(2) for the array assignment
(3) using an array -
Array index starts from 0, the subscript must [foo] xx foo-1 number, will be used if the bounds panic (index out of range)
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An array is part of a value type, default value is passed, so the value will be copied between the array will not affect each other, calling array variable to modify the value of a variable element in the array will not affect the original array variable
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If you wish to modify the array variables of the called function, then directly imparting function pointer array variable is called, by modifying the * (array) [0] = xx array variable changed in a manner
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Go is a part of the length of the array type, if a function as a receiving array variable parameter, then the actual parameters and parameter must be consistent length of the array, i.e., [n] int n must wait in long
Array Case
Case I: Create a 26-letter type byte array, placed AZ respectively, use a for loop to access and print them out.
package main
import "fmt"
func main() {
var myChars [26]byte
for i := 0 ; i <= 25 ; i++ {
myChars[i] = 'A' + byte(i)
}
for i := 0 ; i<= 25 ; i++ {
fmt.Printf("%c",myChars)
}
}
Case II: an array seek the maximum number and subscript
package main
import "fmt"
func main() {
/*
思路：一个数组中假设array[0]为最大，下标即为0，初始化变量值；
这时从数组中第二个数，也就是下标为1的数开始，for循环逐一比较，凡是比0大，那么我就直接修改初始值为当前下标和对应的值
*/
var array = [...]int{10,20,-1,90,220}
maxValue := array[0]
maxIndex := 0
for i :=1 ; i < len(array) ; i++ {
if maxValue < array[i] {
maxValue = array[i]
maxIndex = i
}
}
fmt.Printf("最大值的下标为%v，最大值为%v",maxIndex,maxValue)
}
Case 3: a request and the values in an array, and an average value, for-range
package main
import "fmt"
func main() {
/*
只要要把遍历的数组中的值做一个累加即可
*/
var array = [...]int{10,20,-1,90,220}
sum := 0
for _ , value := range array {
sum += value
}
fmt.Printf("和为%v\n",sum)
fmt.Printf("平均数为%v\n",float64(sum) / float64(len(array))) // 凡是涉及到平均值包含小数的情况，最后一定要保证除数和被除数都是一个数据类型
}
Case four: five random number generation, and reverse print
package main
import (
"fmt"
"math/rand"
"time"
)
func main() {
/*
生成五个随机数需要使用rand.intn()函数，但由于存在seed不变情况，所以需要使用时间函数来使seed随时在变化，保证随机数每次不一致
*/
var intArray [5]int
//记得seed变化一定是纳秒最好，因为秒有些时候因为操作在1秒内，完全有可能一致，所以Unix()不推荐
rand.Seed(time.Now().UnixNano())
for i := 0 ; i < len(intArray) ; i++ {
intArray[i] = rand.Intn(100)
}
fmt.Println(intArray)
/*
交换次数： len(intArray) / 2 无论奇数还是偶数，因为整数的除法是取模
*/
temp := 0
for i := 0 ; i < len(intArray) / 2 ; i++ {
temp = intArray[len(intArray) - 1 - i]
intArray[len(intArray) - 1 - i] = intArray[i]
intArray[i] = temp
}
fmt.Println(intArray)
}
