Constants in Go

 Constants are declared are as follows

package main

import "fmt"

func main() {

    const soundSpeed = 343

    fmt.Println(soundSpeed)

}

Some key points

A value should be assigned to a constant when it is declared

We cannot declare a constant and initialize it later.

Once a constant is created you cannot re-assign a value to that constant.

You cannot assign a value of a constant as a return value of a function, since the value of a constant is evaluated at compile time and methods are evaluated at runtime.

Implicit declaration syntax

Here the compiler will interpret the type as it runs to it

package main

import "fmt"

func main() {

    const soundSpeed = 343

    fmt.Println(soundSpeed)

    fmt.Println(soundSpeed + 3.65)

}

Output:

The following is an example for explicit declaration

package main

import "fmt"

func main() {

    const soundSpeed int = 343

    fmt.Println(soundSpeed)

    fmt.Println(soundSpeed + 3.65)

}

This will throw .\main.go:8:25: constant 3.65 truncated to integer error