Go Constants
Go constant is a value holder whose value once assigned cannot be modified.
const keyword is used to define a constant in Go language.
A constant in go can be of any basic datatype bool, int8, int16, float32, float64, string, etc. Not all datatypes have been mentioned. But you refer Go Datatypes Tutorial.
In this tutorial, we will learn how to define constants of different data types, with examples.
Syntax
The syntax to define a constant in Go language is
const name type = value
where
const
is keyword.name
is the name given to this constant.type
is the type of value we store in this constant.value
is the value we would like to assign this constant with.
Specifying the type is optional for defining a constant. Go language can implicitly derive the datatype from the assigned value. But if we would like to specify the type, we may.
Boolean Constant
In the following example, we define a boolean constant and print the value to console.
Example.go
package main
import "fmt"
func main() {
const c bool = true
fmt.Println(c)
}
Output
true
Numeric Constant
In the following example, we define a numeric constants of type int, float; and print their values to console.
Example.go
package main
import "fmt"
func main() {
const c1 int = 55
fmt.Println(c1)
const c2 float64 = 3.14
fmt.Println(c2)
}
Output
55
3.14
String Constant
In the following example, we define a string constant and print the value to console.
Example.go
package main
import "fmt"
func main() {
const c = "Hello World!"
fmt.Println(c)
}
Output
Hello World!
Conclusion
In this Golang Tutorial, we learned what a constant is in Go language, and how to define constants of various datatypes, with examples.