Variables in Go #

In Go, variables are explicitly declared and used by the compiler to check the type-correctness of function calls. This section covers how to declare, initialize, and use variables in Go.

Declaration and Initialization #

Variables can be declared using the var keyword, followed by the variable name and type. You can also initialize the variable at the time of declaration.

package main
import "fmt"
func main() {
 // Declare a variable of type string
 var name string
 name = "Go"
 fmt.Println("Hello, " + name)
 // Declare and initialize a variable
 var version = 1.17
 fmt.Println("Version:", version)
 // Multiple variables can be declared at once
 var x, y int = 10, 20
 fmt.Println(x, y)
}

Short Variable Declarations #

Inside a function, you can use the := short assignment statement to declare and initialize a variable. The type of the variable is inferred from the value on the right-hand side.

package main
import "fmt"
func main() {
 // Short variable declaration
 language := "Go"
 fmt.Println(language)
 // Multiple assignments
 a, b, c := 1, "hello", true
 fmt.Println(a, b, c)
}

Note: Short variable declarations are only available inside functions.

Constants #

Constants are declared like variables, but with the const keyword. They can be character, string, boolean, or numeric values. Constants cannot be declared using the := syntax.

package main
import "fmt"
const Pi = 3.14
func main() {
 const World = "World"
 fmt.Println("Hello", World)
 fmt.Println("Happy", Pi, "Day")
 const Truth = true
 fmt.Println("Go rules?", Truth)
}

Basic Data Types #

Go has a variety of basic data types, including:

• bool: A boolean value, either true or false.
• string: A sequence of bytes.
• int, int8, int16, int32, int64: Signed integers of various sizes.
• uint, uint8, uint16, uint32, uint64, uintptr: Unsigned integers of various sizes.
• byte: An alias for uint8.
• rune: An alias for int32, represents a Unicode code point.
• float32, float64: Floating-point numbers.
• complex64, complex128: Complex numbers.