Golang filter和sort接口简单示例

下面来介绍Golang两个简单的示例。

1. filter接口

将一个函数作为filter条件去过滤一个数组。

package main

import "fmt"

func compare(filterNum int) bool {
	if filterNum > 3 {
		return true
	}
	return false
}

func filterList(sourceList []int, f func(int) bool) []int {
	targetList := make([]int, len(sourceList))
	for _, num := range sourceList {
		if f(num) {
			targetList = append(targetList, num)
		}
	}
	return targetList
}

func main() {
	testList := []int{1, 2, 3, 4, 5}
	target := filterList(testList, compare)
	fmt.Println("target list: ", target)
}

2. sort接口

根据定义好的ID顺序，对一个数组进行排序

package main

import (
	"fmt"
	"sort"
)

type Country struct {
	id   int
	name string
}

// 将一个数组按照某特定的id顺序进行排序
func sortList(targetList []Country, sortIdList []int) {
	sort.SliceStable(targetList, func(i, j int) bool {
		for _, sortId := range sortIdList {
			if targetList[i].id == sortId {
				return true
			}
			if targetList[j].id == sortId {
				return false
			}
		}
		return false
	})
}

func main() {

	countries := []Country{
		{id: 1, name: "China"},
		{id: 3, name: "France"},
		{id: 2, name: "America"},
	}
	sortIds := []int{3, 2, 1}
	sortList(countries, sortIds)
	fmt.Println("sorted list: ", countries)

}