Map与工厂模式
- Map的value可以是一个方法
- 与Go的Dock type 接口方式一起，可是方便的实现单一方法对象的工厂模式
func TestMap(t *testing.T) {
m := map[int]func(op int) int{}
m[1] = func(op int) int { return op }
m[2] = func(op int) int { return op * op }
m[3] = func(op int) int { return op * op * op }
t.Log(m[1](2), m[2](2), m[3](2))
}
输出
=== RUN TestMap
--- PASS: TestMap (0.00s)
map_test.go:10: 2 4 8
PASS
Process finished with exit code 0
实现 Set
Go的内置集合中没有Set实现，可以map[type]bool
- 元素的唯一性
- 基本操作
- 添加元素
- 判断元素是否存在
- 删除元素
- 元素个数
func TestMapForSet(t *testing.T) {
mySet := map[int]bool{}
mySet[1] = true
n := 3
if mySet[n] {
t.Logf("%d is existing", n)
} else {
t.Logf("%d is not existing", n)
}
mySet[3] = true
t.Log(len(mySet))
delete(mySet,1)
n = 1
if mySet[n] {
t.Logf("%d is existing", n)
} else {
t.Logf("%d is not existing", n)
}
}
输出
=== RUN TestMapForSet
--- PASS: TestMapForSet (0.00s)
map_test.go:20: 3 is not existing
map_test.go:23: 2
map_test.go:29: 1 is not existing
PASS
Process finished with exit code 0