地图

地图 - 删除数据(maps - deleting data)

Go如何从地图中删除数据？ 例如，有

m := map[string]string{ "key1":"val1", "key2":"val2" };

我想通过迭代其键（在某些用途中可能变大）来让m放弃“key1”而不复制整个地图。 给“key1”分配一个零值就足够了，还是将这个键保留在分配值为nil的映射结构中？ 也就是说，如果我稍后迭代地图的键，是否会出现“key1”？

How does one delete data from a map in Go? For example, having

m := map[string]string{ "key1":"val1", "key2":"val2" };

I want to make m drop the "key1" without copying the entire map by iterating over its keys (which could get big in some uses). Is it enough to assign a nil value to "key1", or will that still keep the key in the map structure with an assigned value of nil? That is, if I later iterate over the keys of the map, will "key1" appear?

最满意答案

删除地图元素

内置函数delete从地图m中delete具有键k的元素。

delete(m, k) // remove element m[k] from map m

例如，

package main import "fmt" func main() { m := map[string]string{"key1": "val1", "key2": "val2"} fmt.Println(m) delete(m, "key1") fmt.Println(m) }

输出：

map[key1:val1 key2:val2] map[key2:val2]

Deletion of map elements

The built-in function delete removes the element with key k from a map m.

delete(m, k) // remove element m[k] from map m

For example,

package main import "fmt" func main() { m := map[string]string{"key1": "val1", "key2": "val2"} fmt.Println(m) delete(m, "key1") fmt.Println(m) }

Output:

map[key1:val1 key2:val2] map[key2:val2]