Like in real life, a map is a way of containing data that defines something. Think of the map of New York City. It is a piece of paper that includes data about the city's layoutβ depending on the map type.
Maps are typically handy when you combine different data types because a slice will only permit one data type per-use.
We'll briefly cover Maps so the reader can be aware of them and see when they might be useful.
Syntax
A map uses the 'map' keyword and [type] followed again by 'type.'
package main
func main() {
nyc := map[string]int{
"population": 8000000,
"size": 302,
}
htx := map[string]int{
"population": 2000000,
"size": 665,
}
}
It says a map made of key-pair values of type string and int.
You can have any combination of types with maps, which is when you should consider using them over a slice.
Use case
Although the data is small above it is enough to let us access quick facts about each city with a fast lookup, with syntax similar to a slice.
package main
import "fmt"
func main() {
nyc := map[string]int{
"population": 8000000,
"size": 302,
}
htx := map[string]int{
"population": 2000000,
"size": 665,
}
fmt.Println(htx["population"], nyc["population"])
}
The curious reader should take a look at Go Maps in Action by the GO dev team to get a better sense of when to use 'maps'.
Conclusion
It is enough to know a map and how it generally works. Now, let's move on to part II of automating the boring stuff with go, which contains much more fun practical examples.
Top comments (0)