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Comment by jandrese | Hacker News Reader

BASIC doesn't have typing, so most BASIC interpreters just used floating point everywhere to be a beginner friendly as possible.

The last thing they wanted was someone making their very first app and it behaves like:

    Please enter your name: John Doe

    Please enter how much money you make every day: 80.95

    Congratulations John Doe you made $400 this week!

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Classic BASIC does have typing, it just shoves it into the variable name. E.g. X$ is a string, X% is a 16-bit signed integer, and X# is a double-precision floating point number.

This started with $ for strings in Dartmouth BASIC (when it introduced strings; the first edition didn't have them), and then other BASIC implementations gradually added new suffixes. I'm not sure when % and # showed up specifically, but it was already there in Altair BASIC, and thence spread to its descendants, so it was well-established by 1980s.

Whoa, I never realized this. And I spent much time in high school writing programs in QBASIC.

Interesting. I wonder if this association of $ with strings is related to the use of $ (rather than NUL) as the string terminator for DOS output routines?

I always just figured ‘$’ looks like S, and S is for String

Pretty sure DOS got it from CP/M, but I'm not sure why the latter would have it.

That said, it probably has something to do with earliest 5-bit and 6-bit text encodings that were very constrained wrt control characters, and often originating from punch cards where fixed-length or length-prefixed (https://en.wikipedia.org/wiki/Hollerith_constant) strings were more common. E.g. DEC SIXBIT didn't even have NUL: https://en.wikipedia.org/wiki/Six-bit_character_code

IIRC Python had similar reasoning for making floats the default in version 3 instead of integers, which had been the assumption in 1 and 2 when you entered a number without a decimal. R always did it that way and Julia still assumes integer, which occasionally trips me up when switching languages.

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