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

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

Answer

To convert an array of key-value pairs to a map in Go, you can iterate over the array and insert each key-value pair into the map. This method allows you to create a map from a collection of key-value pairs stored in an array.

✐ Examples

1 Converting a Slice of Pairs to a Map

We can convert a slice of key-value pairs to a map in Go by iterating over the slice and adding each key-value pair to the map.

For example,

We start by declaring and initializing a slice of pairs named pairs with some key-value pairs. In this example, the pairs are represented as structs with two fields: Key and Value.
We declare an empty map named myMap to store the key-value pairs.
We iterate over the slice using a for loop and add each pair to the map.
We print the resulting map to the console using the fmt.Println function to verify the conversion.

Go Program

package main

import "fmt"

// Pair represents a key-value pair
type Pair struct {
    Key   int
    Value int
}

func main() {
    // Declare and initialize a slice of pairs
    pairs := []Pair{
        {1, 10},
        {2, 20},
        {3, 30},
        {4, 40},
        {5, 50},
    }

    // Declare an empty map to store the key-value pairs
    myMap := make(map[int]int)

    // Iterate over the slice and add each pair to the map
    for _, pair := range pairs {
        myMap[pair.Key] = pair.Value
    }

    // Print the resulting map
    fmt.Println("Map from slice of pairs:")
    for key, value := range myMap {
        fmt.Printf("%d: %d\n", key, value)
    }
}

Output

Map from slice of pairs:
1: 10
2: 20
3: 30
4: 40
5: 50

2 Converting a Slice of Tuples to a Map

We can convert a slice of key-value tuples to a map in Go by iterating over the slice and adding each tuple's key-value pair to the map.

For example,

We start by declaring and initializing a slice of tuples named pairs with some key-value pairs. In this example, the tuples are represented as slices with two elements: a key and a value.
We declare an empty map named myMap to store the key-value pairs.
We iterate over the slice using a for loop and add each tuple to the map.
We print the resulting map to the console using the fmt.Println function to verify the conversion.

Go Program

package main

import "fmt"

func main() {
    // Declare and initialize a slice of tuples
    pairs := [][2]int{
        {1, 10},
        {2, 20},
        {3, 30},
        {4, 40},
        {5, 50},
    }

    // Declare an empty map to store the key-value pairs
    myMap := make(map[int]int)

    // Iterate over the slice and add each tuple to the map
    for _, pair := range pairs {
        myMap[pair[0]] = pair[1]
    }

    // Print the resulting map
    fmt.Println("Map from slice of tuples:")
    for key, value := range myMap {
        fmt.Printf("%d: %d\n", key, value)
    }
}

Output

Map from slice of tuples:
1: 10
2: 20
3: 30
4: 40
5: 50

3 Converting a Slice of Structs to a Map

We can convert a slice of structs with key-value fields to a map in Go by iterating over the slice and adding each struct's key-value pair to the map.

For example,

We start by declaring and initializing a slice of structs named pairs with some key-value pairs. Each struct has two fields: Key and Value.
We declare an empty map named myMap to store the key-value pairs.
We iterate over the slice using a for loop and add each struct's key-value pair to the map.
We print the resulting map to the console using the fmt.Println function to verify the conversion.

Go Program

package main

import "fmt"

// Pair represents a key-value pair
type Pair struct {
    Key   int
    Value int
}

func main() {
    // Declare and initialize a slice of structs
    pairs := []Pair{
        {1, 10},
        {2, 20},
        {3, 30},
        {4, 40},
        {5, 50},
    }

    // Declare an empty map to store the key-value pairs
    myMap := make(map[int]int)

    // Iterate over the slice and add each struct's key-value pair to the map
    for _, pair := range pairs {
        myMap[pair.Key] = pair.Value
    }

    // Print the resulting map
    fmt.Println("Map from slice of structs:")
    for key, value := range myMap {
        fmt.Printf("%d: %d\n", key, value)
    }
}

Output

Map from slice of structs:
1: 10
2: 20
3: 30
4: 40
5: 50

Summary

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

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