golang map delete key

In the Go language, map is a very commonly used data structure. It is similar to a dictionary or hash table in other high-level programming languages ​​and can be used to store one-to-one key-value pairs. In most cases, we need to add, find, and update key-value pairs in a map. However, sometimes we may need to delete a key in a map. So, how to delete a map key in Golang?

In Golang, it is very simple to delete a map key. You can use the built-in delete function as follows:

delete(mymap, "key")

The above code will delete the key "key" in mymap.

The following are some important points about using the delete function to delete map keys:

1. deleteThe function can only delete a specified key from the map, but not Delete the entire map.
2. deleteThe function will also not return an error or exception if the key does not exist. If you try to delete a key that does not exist, it will be ignored.
3. If the specified key exists in the map, the delete function will return true, otherwise it will return false.

The following is an example showing how to delete a key in the map:

package main

import "fmt"

func main() {
    mymap := map[string]int{
        "apple":  1,
        "banana": 2,
        "orange": 3,
    }

    fmt.Println(mymap)   //输出：map[apple:1 banana:2 orange:3]

    delete(mymap, "banana")

    fmt.Println(mymap)   //输出：map[apple:1 orange:3]
}

In this example, we first create a key named mymap A map of strings to integers that maps the names of three fruits to their numbers. Next, we called the delete function to delete the "banana" key in mymap. Finally, we print the deleted map. As you can see, the key "banana" has been deleted.

It should be noted that deleting keys in the map does not free memory like clearing a slice or array. If you delete a large number of map keys at the same time, it may take up a lot of memory, so you need to use it with care.

In general, it is very simple to delete a key in a map with Golang. Just call the delete function and pass in the key you want to delete. It should be noted that the deletion operation does not release memory and needs to be used with caution.

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