How to Convert a Map to an Array of Key-Value Pairs in Go - Step by Step Examples

How to Convert a Map to an Array of Key-Value Pairs in Go ?

Answer

To convert a map to an array of key-value pairs in Go, you can use a for loop to iterate over the map and store the key-value pairs in a slice of structs. This provides a convenient way to extract all key-value pairs from the map.

✐ Examples

1 Converting a Map to an Array of Key-Value Pairs Using a for Loop

We can convert a map to an array of key-value pairs in Go using a for loop, which provides a straightforward way to iterate over all key-value pairs and collect them in a slice of structs.

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 declare a struct named KeyValuePair to hold each key-value pair.
We declare a slice named keyValuePairs to store the key-value pairs from the map.
We use a for loop to iterate over the map and append each key-value pair to the keyValuePairs slice.
We print the key-value pairs to the console using a range-based for loop and the fmt.Println function to verify the conversion.

Go Program

package main

import "fmt"

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

    // Declare a struct to hold key-value pairs
    type KeyValuePair struct {
        Key   string
        Value int
    }

    // Declare a slice to store the key-value pairs
    var keyValuePairs []KeyValuePair

    // Convert map to an array of key-value pairs using a for loop
    for key, value := range myMap {
        keyValuePairs = append(keyValuePairs, KeyValuePair{Key: key, Value: value})
    }

    // Print the key-value pairs
    fmt.Println("Key-Value Pairs:")
    for _, pair := range keyValuePairs {
        fmt.Printf("{%s, %d} ", pair.Key, pair.Value)
    }
    fmt.Println()
}

Output

Key-Value Pairs:
{one, 1} {two, 2} {three, 3}

2 Converting an Empty Map to an Array of Key-Value Pairs

We can also convert an empty map to an array of key-value pairs in Go using a for loop, which returns an empty slice when the map is empty.

For example,

We start by declaring an empty map named emptyMap with string keys and integer values.
We declare a struct named KeyValuePair to hold each key-value pair.
We declare a slice named keyValuePairs to store the key-value pairs from the map.
We use a for loop to iterate over the empty map and append each key-value pair to the keyValuePairs slice.
We print the key-value pairs to the console using the fmt.Println function to verify that the slice is empty.

Go Program

package main

import "fmt"

func main() {
    // Declare an empty map
    emptyMap := make(map[string]int)

    // Declare a struct to hold key-value pairs
    type KeyValuePair struct {
        Key   string
        Value int
    }

    // Declare a slice to store the key-value pairs
    var keyValuePairs []KeyValuePair

    // Convert empty map to an array of key-value pairs using a for loop
    for key, value := range emptyMap {
        keyValuePairs = append(keyValuePairs, KeyValuePair{Key: key, Value: value})
    }

    // Print the key-value pairs
    fmt.Println("Key-Value Pairs:", keyValuePairs)
}

Output

Key-Value Pairs: []

3 Converting a Map to an Array of Key-Value Pairs After Adding Elements

We can convert a map to an array of key-value pairs in Go after adding elements using a for loop, which provides an updated slice of all key-value pairs in the map.

For example,

We start by declaring an empty map named dynamicMap with string keys and integer values.
We add some key-value pairs to the map using the map's index notation.
We declare a struct named KeyValuePair to hold each key-value pair.
We declare a slice named keyValuePairs to store the key-value pairs from the map.
We use a for loop to iterate over the map after adding elements and append each key-value pair to the keyValuePairs slice.
We print the key-value pairs to the console using a range-based for loop and the fmt.Println function to verify the updated list of key-value pairs.

Go Program

package main

import "fmt"

func main() {
    // Declare an empty map
    dynamicMap := make(map[string]int)

    // Add elements to the map
    dynamicMap["one"] = 1
    dynamicMap["two"] = 2
    dynamicMap["three"] = 3

    // Declare a struct to hold key-value pairs
    type KeyValuePair struct {
        Key   string
        Value int
    }

    // Declare a slice to store the key-value pairs
    var keyValuePairs []KeyValuePair

    // Convert map to an array of key-value pairs using a for loop
    for key, value := range dynamicMap {
        keyValuePairs = append(keyValuePairs, KeyValuePair{Key: key, Value: value})
    }

    // Print the key-value pairs
    fmt.Println("Key-Value Pairs:")
    for _, pair := range keyValuePairs {
        fmt.Printf("{%s, %d} ", pair.Key, pair.Value)
    }
    fmt.Println()
}

Output

Key-Value Pairs:
{one, 1} {two, 2} {three, 3}

Summary

In this tutorial, we learned How to Convert a Map to an Array of Key-Value Pairs in Go language with well detailed examples.

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