- Create map
- Add item to map
- Lookup item from map
- Delete item from map
- Delete all content from a map
- Count the items in a map
- Put the keys of a map into a slice
Create map
// define map
var m1 map[int]string
// instantiate map
m1 = make(map[int]string)
// implict map instantiation
m2 := make(map[int]string)
// map literal
m3 := map[int]string{
1: "One",
9: "Nine"
}Add item to map
m := map[int]string{
1: "One",
9: "Nine"
}
m[10] = "Ten"
// m contains 1, 9, 10
Lookup item from map
m := map[int]string{
1: "One",
9: "Nine"
}
item, ok := m[9] //item is "Nine; ok is true if the
//key was found, false otherwise
Delete item from map
m := map[int]string{
1: "One",
9: "Nine"
}
delete(m, 9)
//m contains only the `1` item
Delete all content from a map
Assign to the variable pointing to the map a new map:
m := map[int]string{
1: "One",
9: "Nine"
}
m = make(map[int]string) // m is an initialized, empty map
Count the items in a map
m := map[int]string{
1: "One",
9: "Nine"
}
l := len(m) // l == 2
Put the keys of a map into a slice
keys := make([]string, 0, len(m))
for k := range m {
keys = append(keys, k)
}