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.
17 func (p Person
) String() string {
18 return fmt
.Sprintf("%s: %d", p
.Name
, p
.Age
)
21 // ByAge implements sort.Interface for []Person based on
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
}
38 // There are two ways to sort a slice. First, one can define
39 // a set of methods for the slice type, as with ByAge, and
40 // call sort.Sort. In this first example we use that technique.
41 sort
.Sort(ByAge(people
))
44 // The other way is to use sort.Slice with a custom Less
45 // function, which can be provided as a closure. In this
46 // case no methods are needed. (And if they exist, they
47 // are ignored.) Here we re-sort in reverse order: compare
48 // the closure with ByAge.Less.
49 sort
.Slice(people
, func(i
, j
int) bool {
50 return people
[i
].Age
> people
[j
].Age
55 // [Bob: 31 John: 42 Michael: 17 Jenny: 26]
56 // [Michael: 17 Jenny: 26 Bob: 31 John: 42]
57 // [John: 42 Bob: 31 Jenny: 26 Michael: 17]