Constants in Golang

The declaration of a constant is similar to that of a variable, but using the const keyword. The definition format of a constant is similar to the declaration syntax of a variable:

const name type = value

Constants can be characters, strings, booleans, or numbers.

Constants cannot be declared with the := syntax, but the type can be omitted because the compiler can infer its type based on the value of the variable.

// Explicit typed definition
const PI float64 = 3.1415926

// Implicitly typed definition
const PI = 3.1415926

Like variable declarations, multiple constants of different types can also be declared together:

const (
    b  bool = true
    pi float = 3.1415926
)

The following is a complete code example.

package main

import "fmt"

const Pi = 3.1415

func main() {
	const World = "世界"
	fmt.Println("Hello", World)
	fmt.Println("Happy", Pi, "Day")

	const Truth = true
	fmt.Println("Go rules?", Truth)
}

Below is the program output:

Hello 世界
Happy 3.1415 Day
Go rules? true

Golang Constants