golang的sort包中定义了一个名为Interface的interface,还有一个Sort(Interface)的函数:

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type Interface interface {
// Len is the number of elements in the collection.
Len() int
// Less reports whether the element with
// index i should sort before the element with index j.
Less(i, j int) bool
// Swap swaps the elements with indexes i and j.
Swap(i, j int)
}
func Sort(data Interface)

所以,只要一个类型实现了Interface接口,都可以调用Sort函数进行排序,在某些方面用起来感觉比c++中的sort()函数要更直观一点。

放一个官方的例子, ByAge实现了Interface,这样就可以根据自己规定的排序方式,来对ByAge进行排序:

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package main
import (
"fmt"
"sort"
)
type Person struct {
Name string
Age int
}
func (p Person) String() string {
return fmt.Sprintf("%s: %d", p.Name, p.Age)
}
// ByAge implements sort.Interface for []Person based on
// the Age field.
type ByAge []Person
func (a ByAge) Len() int { return len(a) }
func (a ByAge) Swap(i, j int) { a[i], a[j] = a[j], a[i] }
func (a ByAge) Less(i, j int) bool { return a[i].Age < a[j].Age }
func main() {
people := []Person{
{"Bob", 31},
{"John", 42},
{"Michael", 17},
{"Jenny", 26},
}
fmt.Println(people)
sort.Sort(ByAge(people))
fmt.Println(people)
}