I am trying to find a word, other than Boolean, that represents a true or false value. Is there such a word?


I am designing a programming language that is meant to be as easy as possible to understand for those who know nothing of programming. I am trying to name the fundamental types in a way that portrays their purpose to the target audience well. For example, instead of float or even floating-point number, the data type is called decimal. After much thought and use of a popular search engine, I cannot think of an alternative to Boolean for true or false values.

The reason I do not wish to use Boolean is that people who have not been exposed to programming or similar logical thinking simply do not know what it is, which is exactly what I am trying to avoid.

  • For various reasons I often needed programming variables that simply had to be switched between one of two possible values (usually, but not always, True/False or 0/1). In the end I just defined a class called TOGGLE to handle it. Commented Apr 25, 2014 at 20:45
  • @FumbleFingers that's a great one, thank you! Togglable (or maybe switch?) is definitely easy for anyone to understand, even if it is a bit of a mouthful.
    – OMGtechy
    Commented Apr 25, 2014 at 20:50
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    – tchrist
    Commented Apr 25, 2014 at 20:50
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    You will have types based on formats? And I disagree that decimal gives anyone, programmers and non programmers the idea of floating point data. It really doesn't say much to anyone. Other "simple" languages have just used doubles with everything and dispensed with all other numeric types.
    – Oldcat
    Commented Apr 25, 2014 at 23:38
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    Is your floating point stored in base 2? (e.g., is it an IEEE floating point?) (If so, "decimal" is a terrible name.) Most "decimal" types in programming languages store their value in base-10, trading a bit of performance for being able to store whole (decimal) digits. (As opposed to a binary type, which will store fractional decimal digits.) (Also, in this regard, it's not just a "formatting convention": it directly relates to how the value is stored, which has consequences on what values are representable by the type.)
    – Thanatos
    Commented Apr 26, 2014 at 2:57

9 Answers 9


Binary - in the sense of two values, but perhaps still too computer-y a word.

Logical - which has a history of being used in FORTRAN and some COBOLs, and thus might represent a less influenced way of discussing these values.

Truth, Truth-Value - as in whether or not something is true, rather that what is or is not in fact true. That is what Boole called them, after all, and we then named them after him.

Dichotomy / Dichotomous - again, having two values, but also linked to logic more than math.

The same goofy Lisp people who first called the pound sign 'hash', the period 'dot' and the exclamation point 'bang', did so in the same spirit you are working in. They also marked Boolean valued functions with a 'P' (because it looked like a '?') and referred to them as "whether" functions, as in 'whether or not'...

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    Thanks for your help. The only issue I have with binary is that it implies that the data is stored in a bit. It is certainly the best I've heard so far though and more intuitive than Boolean. It amazes me that it's so hard to think of a common English world for this!
    – OMGtechy
    Commented Apr 25, 2014 at 20:23
  • My, you are quick. I don't know whether I added the last one before or after you replied. It might actually be the best option, as it captures the logic. But is seems a bit precious. Commented Apr 25, 2014 at 20:25
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    @OMGtechy The problem with binary is that you are not conveying the data type properly. I think truth value is the more appropriate. This also allows for hinting at having different implementations of what truth value is. You could have a boolean truth value (boolean inheriting from truth value), but you could also have other classes of truth values that allow other implementations, like if you want to work with modal logic. Commented Apr 25, 2014 at 20:44
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    @OMGtechy your first comment made me smile. I find it interesting how you assume that people who don't know Boolean (and can't be bothered to look it up) will be familiar with the concept of a bit. Or storage, for that matter. Come to think of it, even data and imply are pretty big words. If "binary implies that the data is stored in a bit" to you, then here's ten dollars that you've heard Boolean already. So the way I see it, out of all suggestions here only Truth-Value is remotely useful at all. Binary? P? Dichoto-wut? You man serious?
    – RegDwigнt
    Commented Apr 25, 2014 at 21:42
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    Right Logical is one I have forgotten, it has a history of use before Boolean caught on. One assumes that a good implementation of TruthValue in general could, in fact not be stored in a bit. It would probably have to allow a value of Unknown, so it would need at least two. I am still quite keen on Whether, but I go for cute. Think of the declaration. String name, Number dependents, Whether isRegistered, ... Commented Apr 25, 2014 at 21:58

In my programming days I thought of these as Yes/No values: declared global constants Yes and No, with values appropriate to the language (usually 1 and 0), named variables which bore these values FooYN, with Foo representing an appropriate name for the True state (e.g. OnYN, DoneYN) , and if the language supported it declared a YesNo type with two possible values, Yes and No. I found it made my code a tad more readable.

  • + 1. I like this. I'll have to go through all the best candidates with some members of the target audience and mark an answer based upon what they prefer in practice.
    – OMGtechy
    Commented Apr 25, 2014 at 21:49
  • Late to the game as always, but I like where this one goes, and I would call it a 'maybe' value. Because until you know at runtime whether it is 'yes' or 'no', it's just 'maybe'.
    – tuespetre
    Commented Jul 18, 2019 at 19:38
  • @tuespetre Yah; but if 'maybe' is an option, if you actually don't know the value at runtime, then you've gone trivalent: you have to include an 'undefined' value. Is it still a 'boolean' then? Commented Jul 19, 2019 at 20:15
  • @StoneyB ‘maybe’ is a symbol for an indeterminate value that is binary at evaluation time. It’s like there’s a ‘stack’ or ‘scheme’, where in one locale (in this case an unbound environment) it is ternary but in another it is binary.
    – tuespetre
    Commented Jul 21, 2019 at 7:15

I've seen the word flag used, and I like it a lot. Wonder why it hasn't been said here.

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    "flag" is jargon and not really better than "boolean", in my opinion. Commented Apr 26, 2014 at 12:06
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    Eh. Its cultural references are to train lines and mailboxes, right? So it may be stuck in time. As its original references disappear, it may be becoming less of a metaphor and more of a fixed jargon word. (Like radio-button: I've seen literal, physical radio buttons, but my nieces haven't. When they see them on the screen, there is no metaphor, that is just what they call them.) Commented May 2, 2014 at 18:32

Would constative apply?

Constative: being or relating to an utterance (as an assertion, question, or command) that is capable of being judged true or false

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    It terms of meaning it's great, but sadly is no more intuitive than Boolean.
    – OMGtechy
    Commented Apr 25, 2014 at 20:36

A word or expression for "boolean" that is easily identifiable by those who know nothing of programming?

You might pretty well have named that expression already.

True/false values.

  • By this are you referring to having Integer implicitly cast to a Boolean like C and C++ do? If so...interesting; I could eliminate the type altogether.
    – OMGtechy
    Commented Apr 25, 2014 at 22:02
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    @OMGtechy I'm pretty sure that he's just saying that "true/false values" would be an expression that means "boolean". Personally, I'd advise against using implicit casts from integer to boolean for a beginner language as the sole determiner. It leads to confusion for when a person uses a negative number vs 0 vs positive number. And what if they cast a non-int to an int and then treat it like a bool (say, casting a char to an int)? Much confusion for new users.
    – Doc
    Commented Apr 26, 2014 at 5:27

how about a yesno it has easy mnemonics and it's easy to understand. sometimes you have to invent words, that's being done all the time in programming languages :)

Source: IT Professional


How about switch, as in a light switch, which can be either on or off? The only problem is that this is used in many programming languages for multiple choice selections.

  • This is the only one that I was ever comfortable with, especially when I had to deal with other dualities.
    – Spencer
    Commented Mar 28, 2018 at 22:55
  • Some switches have more than 2 values or positions. Commented Feb 22, 2019 at 20:29

A Proposition:

From Wikipedia

Aristotelian logic identifies a proposition as a sentence which affirms or denies a predicate of a subject. An Aristotelian proposition may take the form "All men are mortal" or "Socrates is a man."


This may be too late but anyway... I think the word 'Trueness' could be the one that you look for. 'Trueness' can be considered as a state to be or not to be True.

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    Welcome to ELU, please consider adding sources to support your answers. In this case, I don't think trueness encapsulates that is binary (i.e. either true or false).
    – JJJ
    Commented Mar 28, 2018 at 22:34
  • I found this answer useful in my hunt to name an enum type with 3 fixed values - Default, False, True. You used the word state and that was it. Thanks.
    – IAbstract
    Commented Dec 22, 2022 at 12:34

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