Home/ Questions/Q 7742919
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-01T09:24:02+00:00

Note: I am not exactly sure what to name the question, so if someone

  • 0

Note: I am not exactly sure what to name the question, so if someone has a better idea please edit it.

I will jump right into the question, since there isn’t any fore-explaining required.

This code:

!foo = true

generates this warning

warning: found = in conditional, should be ==

I would understand if this was happening after an if or unless statement, but this couldn’t be further away from them (exaggerating). I do realise I could use:

foo = true
!foo

I suppose, the warning isn’t a big deal, but it is a bit irritating that Ruby is assuming I am doing something wrong—when I am not.

Questions:

  • Is this a bug?
  • Can the warning be disabled?

Thanks!

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    Is legal. Not a bug. The warning can be suppressed.

    You can disable the warning with:

    $VERBOSE = nil

    It’s interesting, $VERBOSE is a case where setting something to false does something different than setting it to nil.

    By the way, the other answers, at least initially, tend to assume that Ruby parses the expression as 

    (!foo) = true

    … but that’s not the case. It is parsed as:

    !(foo = true)

    … and so it’s doing exactly what the OP wanted. And there is no specification or ratified standard for Ruby, so if it works in MRI (the reference implementation) then it’s legal.

    • 0