How to create a Map with Initial Key-Value Pairs in Go

How to create a Map with Initial Key-Value Pairs in Go ?

Answer

To create a map with initial key-value pairs in Go, you can use the map literal syntax. This creates a new map object with predefined key-value pairs.

✐ Examples

1 Creating a Map with Initial Key-Value Pairs

We can create a map in Go with initial key-value pairs using the map literal syntax, which initializes a map with predefined key-value pairs.

For example,

We start by declaring a variable named myMap. This variable will hold our map with initial key-value pairs.
We use the map literal syntax to create a new map object. In Go, the map literal syntax allows us to specify key-value pairs directly within curly braces.
The newly created map is now assigned to the myMap variable. In this example, the map has string keys and integer values.
We can now perform various operations on this map, such as adding more key-value pairs, checking for the presence of keys, and retrieving values.

Go Program

package main

import "fmt"

func main() {
    // Declare a map with initial key-value pairs
    myMap := map[string]int{
        "one": 1,
        "two": 2,
        "three": 3,
    }

    // Operations on the map
    for key, value := range myMap {
        fmt.Printf("%s: %d\n", key, value)
    }
}

Output

one: 1
two: 2
three: 3

2 Creating a Map with Different Key-Value Types

We can create a map in Go with initial key-value pairs of different types using the map literal syntax.

For example,

We start by declaring a variable named studentGrades. This variable will hold our map with initial key-value pairs where keys are strings (student names) and values are characters (grades).
We use the map literal syntax to create a new map object. In Go, the map literal syntax allows us to specify key-value pairs directly within curly braces.
The newly created map is now assigned to the studentGrades variable. In this example, the map has string keys and rune values representing grades.
We can now perform various operations on this map, such as adding more key-value pairs, checking for the presence of keys, and retrieving values.

Go Program

package main

import "fmt"

func main() {
    // Declare a map with initial key-value pairs
    studentGrades := map[string]rune{
        "Alice": 'A',
        "Bob": 'B',
        "Charlie": 'C',
    }

    // Operations on the map
    for key, value := range studentGrades {
        fmt.Printf("%s: %c\n", key, value)
    }
}

Output

Alice: A
Bob: B
Charlie: C

3 Creating a Map with Integer Keys and Float Values

We can create a map in Go with initial key-value pairs where keys are integers and values are floats using the map literal syntax.

For example,

We start by declaring a variable named productPrices. This variable will hold our map with initial key-value pairs where keys are integers (product IDs) and values are floats (prices).
We use the map literal syntax to create a new map object. In Go, the map literal syntax allows us to specify key-value pairs directly within curly braces.
The newly created map is now assigned to the productPrices variable. In this example, the map has integer keys and float64 values.
We can now perform various operations on this map, such as adding more key-value pairs, checking for the presence of keys, and retrieving values.

Go Program

package main

import "fmt"

func main() {
    // Declare a map with initial key-value pairs
    productPrices := map[int]float64{
        101: 29.99,
        102: 39.99,
        103: 49.99,
    }

    // Operations on the map
    for key, value := range productPrices {
        fmt.Printf("Product %d: $%.2f\n", key, value)
    }
}

Output

Product 101: $29.99
Product 102: $39.99
Product 103: $49.99

Summary

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

◀ Previous Next ▶

Go Tutorials

Go Programs

Go How-Tos

How to create a Map with Initial Key-Value Pairs in Go