1 // Copyright 2011 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package sort_test 6 7 import ( 8 "fmt" 9 "sort" 10 ) 11 12 type Person struct { 13 Name string 14 Age int 15 } 16 17 func (p Person) String() string { 18 return fmt.Sprintf("%s: %d", p.Name, p.Age) 19 } 20 21 // ByAge implements sort.Interface for []Person based on 22 // the Age field. 23 type ByAge []Person 24 25 func (a ByAge) Len() int { return len(a) } 26 func (a ByAge) Swap(i, j int) { a[i], a[j] = a[j], a[i] } 27 func (a ByAge) Less(i, j int) bool { return a[i].Age < a[j].Age } 28 29 func Example() { 30 people := []Person{ 31 {"Bob", 31}, 32 {"John", 42}, 33 {"Michael", 17}, 34 {"Jenny", 26}, 35 } 36 37 fmt.Println(people) 38 sort.Sort(ByAge(people)) 39 fmt.Println(people) 40 41 // Output: 42 // [Bob: 31 John: 42 Michael: 17 Jenny: 26] 43 // [Michael: 17 Jenny: 26 Bob: 31 John: 42] 44 } 45
