Go 1.21新内置函数min、max和clear的用法详解

type Ordered interface {
	~int | ~int8 | ~int16 | ~int32 | ~int64 |
		~uint | ~uint8 | ~uint16 | ~uint32 | ~uint64 | ~uintptr |
		~float32 | ~float64 |
		~string
}

package main
import "fmt"
func main() {
	var a1, a2, a3 int64 = 1, 2, 3
	maxA := max(a1, a2, a3)
	fmt.Printf("%T, %d\n", maxA, maxA) // int64, 3
	var f1, f2, f3 float64 = 1.0, 2.0, 3.0
	maxF := max(f1, f2, f3)
	fmt.Printf("%T, %.1f\n", maxF, maxF) // float64, 3.0
	// 
	var s1, s2, s3 string = "aaa", "aab", "aac"
	maxS := max(s1, s2, s3)
	fmt.Println(maxS) // aac
}

package main
import "fmt"
func main() {
	var a1, a2, a3 int64 = 1, 2, 3
	maxA := min(a1, a2, a3)
	fmt.Printf("%T, %d\n", maxA, maxA) // int64, 1
	var f1, f2, f3 float64 = 1.0, 2.0, 3.0
	maxF := min(f1, f2, f3)
	fmt.Printf("%T, %.1f\n", maxF, maxF) // float64, 1.0
	// 按照字节逐个比较字符串的内容
	var s1, s2, s3 string = "aaa", "aab", "aac"
	maxS := min(s1, s2, s3)
	fmt.Printf("%T, %s\n", maxS, maxS) // string, aaa
}

package main
import "fmt"
type MySlice[T any] []T  
type MyMap[K comparable, V any] map[K]V
func main() {
	s := []int{1, 2, 3, 4}
	clear(s)
	fmt.Printf("len: %d, cap: %d, elems: %v\n", len(s), cap(s), s) // len: 4, cap: 4, elems: [0 0 0 0]
	m := map[string]int{"Apple": 1, "Banana": 2}
	clear(m)
	fmt.Printf("len: %d, elems: %v\n", len(m), m) // len: 0, elems: map[]
	// 自定义泛型切片类型变量
	mySlice := MySlice[string]{"公众号：Go技术干货", "陈明勇", "Gopher"}
	clear(mySlice)
	fmt.Printf("len: %d, cap: %d, elems: %v\n", len(mySlice), cap(mySlice), mySlice) // len: 3, cap: 3, elems: [  ]
	// 自定义泛型 map 类型变量
	myMap := MyMap[string, int]{"Apple": 1, "Banana": 2}
	clear(myMap)
	fmt.Printf("len: %d, elems: %v\n", len(myMap), myMap) // len: 0, elems: map[]
}