Is there an easy/simple means of converting a slice into a map in Golang? Like converting an array into hash in perl is easy to do with simple assignment like %hash = @array
this above will convert all the elements in the array into a hash, with keys being even-numbered index elements while the values will be odd-numbered index elements of the array.
In my Go code, I have slices of string and would like to convert it into a map. I am wondering if there is a Go's library code to do this.
func main() {
var elements []string
var elementMap map[string]string
elements = []string{"abc", "def", "fgi", "adi"}
}
elements slice should be converted into map of strings, elementMap
.
thanks
Use a for loop:
elements = []string{"abc", "def", "fgi", "adi"}
elementMap := make(map[string]string)
for i := 0; i < len(elements); i +=2 {
elementMap[elements[i]] = elements[i+1]
}
runnable example on the playground
The standard library does not have a function to do this.
There is currently no way to do it the perl way. You just have to iterate the slice, and place the slice elements in your map, e.g. as the map's key:
func main() {
var elements []string
var elementMap map[string]string
elements = []string{"abc", "def", "fgi", "adi"}
// initialize map
elementMap = make(map[string]string)
// put slice values into map
for _, s := range elements {
elementMap[s] = s
// or just keys, without values: elementMap[s] = ""
}
// print map
for k := range elementMap {
fmt.Println(k)
}
}
Depending on what you want to do, you have to keep one thing in mind: map keys are unique, so if your slice contains duplicate strings you might want to keep count by using a map[string]int
:
func main() {
var elements []string
var elementMap map[string]int
elements = []string{"abc", "def", "fgi", "adi", "fgi", "adi"}
// initialize map
elementMap = make(map[string]int)
// increment map's value for every key from slice
for _, s := range elements {
elementMap[s]++
}
// print map
for k, v := range elementMap {
fmt.Println(k, v)
}
}
And you can always wrap that functionality in a func:
func sliceToStrMap(elements []string) map[string]string {
elementMap := make(map[string]string)
for _, s := range elements {
elementMap[s] = s
}
return elementMap
}
func sliceToIntMap(elements []string) map[string]int {
elementMap := make(map[string]int)
for _, s := range elements {
elementMap[s]++
}
return elementMap
}
If looking for a library you can use go-funk. This code may be less performant and not idiomatic in Go until we have Generics.
var elements = []string{"abc", "def", "fgi", "adi"}
elementsMap := funk.Map(
funk.Chunk(elements, 2),
func(x []string) (string, string) { // Slice to Map
return x[0], x[1]
},
)
fmt.Println(elementsMap) // map[abc:def fgi:adi]
https://play.golang.org/p/-t-33z4aKM_j
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