对map进行排序

代码

package main

import (
    "fmt"
    "sort"
)

// 给key排序，从小到大
func Map(maps map[int]string) (keys []int) {
    keys = []int{}
    // 得到各个key
    for key := range maps {
        keys = append(keys, key)
    }
    // 给key排序，从小到大
    sort.Sort(sort.IntSlice(keys)) // 或者 sort.Ints(keys)
    // 如果key是字符串,可以使用sort.Strings(keys)
    return
}

// 给key排序，从大到小
func Map2(maps map[int]string) (keys []int) {
    keys = []int{}
    // 得到各个key
    for key := range maps {
        keys = append(keys, key)
    }
    // 给key排序，从大到小
    sort.Sort(sort.Reverse(sort.IntSlice(keys)))
    return
}
func main() {
    maps := map[int]string{
        1: "星期一",
        2: "星期二",
        3: "星期三",
        4: "星期四",
        5: "星期五",
        6: "星期六",
        7: "星期天",
    }
    keys := Map2(maps)
    // 遍历map
    for _, key := range keys {
        fmt.Printf("key = %v,value = %v\n", key, maps[key])
    }
}

切片排序

代码

package main

import (
    "fmt"
    "sort"
)

type Person struct {
    Name string
    Age  int
}

type ByNum []Person

func (a ByNum) Len() int           { return len(a) }
func (a ByNum) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
func (a ByNum) Less(i, j int) bool { return a[i].Age < a[j].Age }

func main() {
    people := []Person{
        {"Alice", 25},
        {"Bob", 30},
        {"Charlie", 20},
    }

    fmt.Println("Before sorting:")
    fmt.Println(people)

    sort.Sort(ByNum(people))

    fmt.Println("After sorting:")
    fmt.Println(people)
}