英文:
How to delete an element from a slice that's inside a map?
问题
我有一个包含键和多个值的地图。
我想要做的是从值中删除一个单独的值。
示例：
map1 := make(map[string][]string)
str1 := []string{"Jon", "Doe", "Captain", "America"}
str2 := "Doe"
map1["p1"] = str1
在上面的示例中，如果值在str2中存在，我想要从"p1"中删除该值，即"Doe"。
删除该值后，地图应该是这样的：
p1:[Jon Captain America]
这个可能吗？还是我需要重新编写整个地图？
英文:
I have a a map which has a key and multiple values for that key.
What i want to do is delete a single value from values.
Example:
map1 := make(map[string][]string)
str1 := []string{"Jon", "Doe", "Captain", "America"}
str2 := "Doe"
map1["p1"] = str1
In the above example I want to remove value form the "p1" if it is present in str2, in my case it is "Doe"
after removing the value map should be like this
p1:[Jon Captain America]
Is this possible or do i have to rewrite the whole map again?
答案1
得分: 3
在一个映射（map）的切片（slice）中，不可能直接“原地”删除一个元素。你需要先从映射中获取切片，然后从切片中删除元素，最后将结果存储回映射中。
如果你正在使用Go1.18，可以使用golang.org/x/exp/slices包来通过值找到元素的索引，然后从切片中删除它。
以下是一个示例代码：
package main
import (
"fmt"
"golang.org/x/exp/slices"
)
func main() {
map1 := make(map[string][]string)
str1 := []string{"Jon", "Doe", "Captain", "America"}
str2 := "Doe"
map1["p1"] = str1
idx := slices.Index(map1["p1"], str2)
map1["p1"] = slices.Delete(map1["p1"], idx, idx+1)
fmt.Println(map1)
}
你可以在以下链接中查看和运行代码：https://go.dev/play/p/EDTGAJT-VdM
英文:
It's not possible to "in place" delete an element from a slice that's inside a map. You need to first get the slice from the map, delete the element from the slice, and then store the result of that in the map.
For finding the element's index by its value and then deleting it from the slice you can use the golang.org/x/exp/slices package if you are using Go1.18.
package main
import (
"fmt"
"golang.org/x/exp/slices"
)
func main() {
map1 := make(map[string][]string)
str1 := []string{"Jon", "Doe", "Captain", "America"}
str2 := "Doe"
map1["p1"] = str1
idx := slices.Index(map1["p1"], str2)
map1["p1"] = slices.Delete(map1["p1"], idx, idx+1)
fmt.Println(map1)
}
答案2
得分: 1
package main
func main() {
var sessions = map[string]chan int{}
delete(sessions, "moo")
}
或者
package main
func main() {
var sessions = map[string]chan int{}
sessions["moo"] = make(chan int)
_, ok := sessions["moo"]
if ok {
delete(sessions, "moo")
}
}
以上是要翻译的内容。
英文:
package main
func main () {
var sessions = map[string] chan int{};
delete(sessions, "moo");
}
or
package main
func main () {
var sessions = map[string] chan int{};
sessions["moo"] = make (chan int);
_, ok := sessions["moo"];
if ok {
delete(sessions, "moo");
}
}
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论