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Kervie Sazon
Kervie Sazon

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Go Learning Notes - Part 6: Maps & Type Conversion (strconv)

#beginners #devjournal #go #learning

Today I learned about Maps in Go and how to properly handle type conversion using the strconv package.

Maps in Go

I improved my booking app by replacing simple slices with maps to store structured user data.

Instead of storing only names like this:

bookings := []string{}
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I now use a slice of maps:

bookings := make([]maps[string]string, 0)
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Each user booking is stored as a map:

userData := make([]map[string]string)
userData["firstName"] = fName
userData["lastName"] = lName
userData["email"] = email
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This makes the data more organized, easier to access and more scalable for real-world applications.

Now I can easily access specific values like:

bookings["firsName"]
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Type Conversion in Go (strconv)

In my app, userTickets is a uint, but maps store values as string.
So I needed to convert the number into a string before storing it.

Solution: strconv.FormatUint()

userData["numberOfTickets"] = strconv.FormatUint(uint64(userTickeets), 10)
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What’s happening here?

  • uint64(userTickets) - Convert uint to uint64
  • 10 - Base 10 (decimal)
  • Returns a string

Now the ticket number can safely be stored inside the map.

For Better Understanding

Slice of Maps Declaration

var (
    bookings = make([]map[string]string, 0)
)
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Creating and Storing User Data in a Map

func bookTicket(userTickets uint, fName string, lName string, email string) {
    RemainingTickets = RemainingTickets - userTickets

    // create a map for a user
    userData := make(map[string]string)
    userData["firstName"] = fName
    userData["lastName"] = lName
    userData["email"] = email
    userData["numberOfTickets"] = strconv.FormatUint(uint64(userTickets), 10)

    bookings = append(bookings, userData)
}
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Accessing Map Values Inside a Loop

func getFNames() []string {
    firstNames := []string{}
    for _, booking := range bookings {
        firstNames = append(firstNames, booking["firstName"])
    }
    return firstNames
}
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Import for Type Conversion

import "strconv"
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This lesson made my booking application more structured and closer to real-world development.
Using maps helped me understand how Go handles data organization, and learning strconv improved my understanding of Go’s strict type system.

In summary, I learned how to use maps in Go to store structured user data more efficiently by creating a slice of map[string]string. I understood how to access specific values from a map while looping through the slice, such as retrieving all first names. I also learned that Go is strongly typed and requires explicit type conversion when working with different data types. Using strconv.FormatUint() helped me convert a uint value into a string so it can be stored properly inside a map.

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