Dave Cheney #golang pop quiz

#go

What is the output for this program?

Source: https://twitter.com/davecheney/status/1215006731610124288

package main

import (
    "fmt"
)

func isEven(v int) bool {
    if (v % 2) == 1 {
        goto false
    }
    return !false
false:
    return false

}

func main() {
    fmt.Println(isEven(2020))
}

Top comments (9)

Akshay Bharambe • Jan 9 '20 • Edited

Thanks, got to know that "true" and "false" can be a variable name or label. Here is another version.

package main

import (
    "fmt"
)

func isEven(v int) bool {
    false := !true

    if (v % 2) == 1 {
        goto true
    }
    return true
true:
    return false

}

func main() {
    fmt.Println(isEven(2020))
}

Manigandan Dharmalingam • Jan 9 '20

That's cool

Comment hidden by post author - thread only accessible via permalink

Nicolas Lepage • Jan 9 '20

Hi Manigandand

First of all welcome to dev.to and congrats for this first post.

I noticed the program of your post comes from a tweet from Dave Cheney:

Dave Cheney

@davecheney

#golang pop quiz: what does this program print?

package main

import (
"fmt"
)

func isEven(v int) bool {
if v%2 == 1 {
goto false
}
return !false
false:
return false
}

func main() {
fmt.Println(isEven(2020))
}

20:25 PM - 08 Jan 2020

3 32

I think it would be better if you cited this source.

I don't think dev.to has any rules against this kind of content reuse, and I'm not personnaly against it, however I find it more honest to always cite sources.