如何使用多个排序参数对结构进行排序? [英] How to sort struct with multiple sort parameters?

问题描述

我有一个成员数组/切片:

I have an array/slice of members:

type Member struct {
    Id int
    LastName string
    FirstName string
}

var members []Member

我的问题是如何按LastName然后按FirstName对其进行排序.

My question is how to sort them by LastName and then by FirstName.

推荐答案

使用 sort.Slice (从Go 1.8开始可用)或 sort.Sort 函数对值的一部分进行排序.

Use the sort.Slice (available since Go 1.8) or the sort.Sort function to sort a slice of values.

使用这两个功能，应用程序都提供了一个功能，用于测试一个slice元素是否小于另一个slice元素.要按姓氏和名字排序，请比较姓氏和名字:

With both functions, the application provides a function that tests if one slice element is less than another slice element. To sort by last name and then first name, compare last name and then first name:

if members[i].LastName < members[j].LastName {
    return true
}
if members[i].LastName > members[j].LastName {
    return false
}
return members[i].FirstName < members[j].FirstName

less函数是使用带有sort.Slice的匿名函数指定的:

The less function is specified using an anonymous function with sort.Slice:

var members []Member
sort.Slice(members, func(i, j int) bool {
    if members[i].LastName < members[j].LastName {
        return true
    }
    if members[i].LastName > members[j].LastName {
        return false
    }
    return members[i].FirstName < members[j].FirstName
})

less函数通过带有sort.Sort函数的接口指定:

The less function is specified with through an interface with the sort.Sort function:

type byLastFirst []Member

func (members byLastFirst) Len() int           { return len(members) }
func (members byLastFirst) Swap(i, j int)      { members[i], members[j] = members[j], members[i] }
func (members byLastFirst) Less(i, j int) bool { 
    if members[i].LastName < members[j].LastName {
       return true
    }
    if members[i].LastName > members[j].LastName {
       return false
    }
    return members[i].FirstName < members[j].FirstName
}

sort.Sort(byLastFirst(members))

除非性能分析表明排序是一个热点，否则请使用最适合您的应用程序的功能.

Unless performance analysis shows that sorting is a hot spot, use the function that's most convenient for your application.

这篇关于如何使用多个排序参数对结构进行排序?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！