Go Variable Examples

In this example, we will show you how to declare and use variables in Go with examples.

Variables are used to store values. They are labels given to the values. Go uses the var keyword to declare a list of variables. We can also use the := shorthand syntax to declare variables.

1. Go declare variable example

In the example, we declare and initialize two variables. Later, we print them.

package main

import "fmt"

func main() {

    var i int = 10
    var w float64 = 10.5

    fmt.Println(i)
    fmt.Println(w)
}

Output:

10
10.5

2. Go declare multiple variables example

With the var keyword, we can declare multiple variables at once.

The below example shows how to declare multiple variables with var.

package main

import "fmt"

func main() {

    var i, j, k = 1, 2, 3

    var (
        firstName       = "John"
        lastName = "Cena"
    )

    fmt.Println(i, j, k)
    fmt.Printf("%s  %s\n", firstName, lastName)
}

Output:

1 2 3
John  Cena

3. Go shorthand variable declaration example

Inside a function, the := short assignment statement can be used in place of a var declaration with implicit type.

The example declares two variables with the shorthand notation.

package main

import "fmt"

func main() {

    name := "John"
    age := 24

    fmt.Println(name, age)
}

Output:

John 24

4. One more Go variable example

package main

import "fmt"

func main() {

    var a = "string"
    fmt.Println(a)

    var b, c int = 3, 4 // Go declare multiple variables
    fmt.Println(b, c)

    var d = true
    fmt.Println(d)

    var e int
    fmt.Println(e)

    f := "apple" // Go shorthand variable declaration
    fmt.Println(f)
}

Output:

string
3 4
true
0
apple

5. More Go Variable Examples

package main

import "fmt"

func main() {
	// Step 1: Declare a variable with the 'var' keyword.
	var message string
	message = "Hello, Go!"

	// Step 2: Initialize a variable at the time of declaration.
	var greeting string = "Welcome to the world of Go!"

	// Step 3: Use shorthand ':=' syntax to declare and initialize.
	name := "Gopher"

	// Step 4: Demonstrate variable assignment after declaration.
	var age int
	age = 10

	// Step 5: Print the variables to output.
	fmt.Println(message)
	fmt.Println(greeting)
	fmt.Println("Name:", name)
	fmt.Printf("Age: %d\n", age)
}

Output:

Hello, Go!
Welcome to the world of Go!
Name: Gopher
Age: 10

Explanation:

1. package main - The package declaration for the executable program.

2. import "fmt" - The import statement for the Format package, used for formatted output.

3. var message string - Declaration of a string variable message using the var keyword. It's initialized in the next line.

4. message = "Hello, Go!" - Assignment to the previously declared variable message.

5. var greeting string = "Welcome to the world of Go!" - Declaration and initialization of the greeting variable on the same line.

6. name := "Gopher" - The shorthand syntax for declaring and initializing the name variable. This syntax infers the type from the assigned value.

7. var age int and age = 10 - Declaration of an int variable age followed by assignment on the next line.

8. fmt.Println(...) and fmt.Printf(...) - Functions used to print the variables to the standard output.

9. The output displays the initialized values for each of the variables, demonstrating different ways to declare and initialize variables in Go.