array sorting

Examples of how to sort an array

Node.js

  1. const stringArray = ['a', 'd', 'z', 'b', 'c', 'y']
  2. const stringArraySortedAsc = stringArray.sort((a, b) => a > b ? 1 : -1)
  3. console.log(stringArraySortedAsc)
  5. const stringArraySortedDesc = stringArray.sort((a, b) => a > b ? -1 : 1)
  6. console.log(stringArraySortedDesc)
  9. const numberArray = [1, 3, 5, 9, 4, 2, 0]
  10. const numberArraySortedAsc = numberArray.sort((a, b) => a - b)
  11. console.log(numberArraySortedAsc)
  13. const numberArraySortedDesc = numberArray.sort((a, b) => b - a)
  14. console.log(numberArraySortedDesc)
  16. const collection = [
  17.     {
  18.         name: "Li L",
  19.         age: 8
  20.     },
  21.     {
  22.         name: "Json C",
  23.         age: 3
  24.     },
  25.     {
  26.         name: "Zack W",
  27.         age: 15
  28.     },
  29.     {
  30.         name: "Yi M",
  31.         age: 2
  32.     }
  33. ]
  35. const collectionSortedByAgeAsc = collection.sort((a, b) => a.age - b.age)
  36. console.log(collectionSortedByAgeAsc)
  38. const collectionSortedByAgeDesc = collection.sort((a, b) => b.age - a.age)
  39. console.log(collectionSortedByAgeDesc)

Output

  1. [ 'a', 'b', 'c', 'd', 'y', 'z' ]
  2. [ 'z', 'y', 'd', 'c', 'b', 'a' ]
  3. [ 0, 1, 2, 3, 4, 5, 9 ]
  4. [ 9, 5, 4, 3, 2, 1, 0 ]
  5. [ { name: 'Yi M', age: 2 },
  6.   { name: 'Json C', age: 3 },
  7.   { name: 'Li L', age: 8 },
  8.   { name: 'Zack W', age: 15 } ]
  9. [ { name: 'Zack W', age: 15 },
  10.   { name: 'Li L', age: 8 },
  11.   { name: 'Json C', age: 3 },
  12.   { name: 'Yi M', age: 2 } ]

Go

  1. package main
  3. import (
  4.     "fmt"
  5.     "sort"
  6. )
  8. type Person struct {
  9.     Name string
  10.     Age  int
  11. }
  13. type PersonCollection []Person
  15. func (pc PersonCollection) Len() int {
  16.     return len(pc)
  17. }
  19. func (pc PersonCollection) Swap(i, j int) {
  20.     pc[i], pc[j] = pc[j], pc[i]
  21. }
  23. func (pc PersonCollection) Less(i, j int) bool {
  24.     // asc
  25.     return pc[i].Age < pc[j].Age
  26. }
  28. func main() {
  29.     intList := []int{1, 3, 5, 9, 4, 2, 0}
  31.     // asc
  32.     sort.Ints(intList)
  33.     fmt.Println(intList)
  34.     // desc
  35.     sort.Sort(sort.Reverse(sort.IntSlice(intList)))
  36.     fmt.Println(intList)
  38.     stringList := []string{"a", "d", "z", "b", "c", "y"}
  40.     // asc
  41.     sort.Strings(stringList)
  42.     fmt.Println(stringList)
  43.     // desc
  44.     sort.Sort(sort.Reverse(sort.StringSlice(stringList)))
  45.     fmt.Println(stringList)
  47.     collection := []Person{
  48.         {"Li L", 8},
  49.         {"Json C", 3},
  50.         {"Zack W", 15},
  51.         {"Yi M", 2},
  52.     }
  54.     // asc
  55.     sort.Sort(PersonCollection(collection))
  56.     fmt.Println(collection)
  57.     // desc
  58.     sort.Sort(sort.Reverse(PersonCollection(collection)))
  59.     fmt.Println(collection)
  60. }

Output

  1. [0 1 2 3 4 5 9]
  2. [9 5 4 3 2 1 0]
  3. [a b c d y z]
  4. [z y d c b a]
  5. [{Yi M 2} {Json C 3} {Li L 8} {Zack W 15}]
  6. [{Zack W 15} {Li L 8} {Json C 3} {Yi M 2}]