How to Clear All Key-Value Pairs from a Map in Go - Step by Step Examples

How to Clear All Key-Value Pairs from a Map in Go ?

Answer

To clear all key-value pairs from a map in Go, you can reinitialize the map or delete each key individually using a loop. Both methods effectively empty the map.

✐ Examples

1 Clearing All Key-Value Pairs by Reinitializing the Map

We can clear all key-value pairs from a map in Go by reinitializing the map, which removes all elements from the map.

For example,

We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We reinitialize the map by assigning a new empty map to the variable myMap.
We print the contents of the map to the console using the fmt.Println function to verify that the map is empty.

Go Program

package main

import "fmt"

func main() {
    // Declare and initialize a map
    myMap := map[string]int{
        "one": 1,
        "two": 2,
        "three": 3,
    }

    // Clear all key-value pairs by reinitializing the map
    myMap = make(map[string]int)

    // Print the contents of the map
    fmt.Println(myMap)
}

Output

map[]

2 Clearing an Already Empty Map

We can reinitialize an already empty map in Go, and it will still be empty.

For example,

We start by declaring and initializing an empty map named myMap. In this example, the map has string keys and integer values.
We reinitialize the map by assigning a new empty map to the variable myMap.
We print the contents of the map to the console using the fmt.Println function to verify that the map is still empty.

Go Program

package main

import "fmt"

func main() {
    // Declare and initialize an empty map
    myMap := map[string]int{}

    // Clear the map by reinitializing it
    myMap = make(map[string]int)

    // Print the contents of the map
    fmt.Println(myMap)
}

Output

map[]

3 Clearing a Map by Deleting Each Key Individually

We can delete each key individually from a map to clear all key-value pairs in Go.

For example,

We start by declaring and initializing a map named myMap and inserting some key-value pairs into it. In this example, the map has string keys and integer values.
We iterate over the map using a range-based for loop and delete each key using the delete function.
We print the contents of the map to the console using the fmt.Println function to verify that the map is empty.

Go Program

package main

import "fmt"

func main() {
    // Declare and initialize a map
    myMap := map[string]int{
        "one": 1,
        "two": 2,
        "three": 3,
    }

    // Clear the map by deleting each key individually
    for key := range myMap {
        delete(myMap, key)
    }

    // Print the contents of the map
    fmt.Println(myMap)
}

Output

map[]

Summary

In this tutorial, we learned How to Clear All Key-Value Pairs from a Map in Go language with well detailed examples.

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How to Clear All Key-Value Pairs from a Map in Go - Step by Step Examples