golang map prints out of order
dictionary, go
Solution
Code:
func DemoSortMap() (int, error) {
fmt.Println("use an array to access items by number:")
am := [2]string{"jan", "feb"}
for i, n := range am {
fmt.Printf("%2d: %s\n", i, n)
}
fmt.Println("maps are non-sorted:")
mm := map[int]string{2: "feb", 1: "jan"}
for i, n := range mm {
fmt.Printf("%2d: %s\n", i, n)
}
fmt.Println("access items via sorted list of keys::")
si := make([]int, 0, len(mm))
for i := range mm {
si = append(si, i)
}
sort.Ints(si)
for _, i := range si {
fmt.Printf("%2d: %s\n", i, mm[i])
}
return 0, nil
}
(most of it stolen from M. Summerfield's book)
output:
use an array to access items by number:
0: jan
1: feb
maps are non-sorted:
2: feb
1: jan
access items via sorted list of keys::
1: jan
2: feb
Problem
Why is the map printing out of order, and how do I get it in to order? ``` package main import ( "fmt" ) type monthsType struct { no int text string } var months = map[int]string{ 1:"January", 2:"Fabruary", 3:"March", 4:"April", 5:"May", 6:"June", 7:"July", 8:"August", 9:"September", 10:"October", 11:"Novenber", 12:"December", } func main(){ for no, month := range months { fmt.Print(no) fmt.Println("-" + month) } } ``` Prints out: ``` 10-October 7-July 1-January 9-September 4-April 5-May 2-Fabruary 12-December 11-Novenber 6-June 8-August 3-March ```