How JavaScript Works

What Hacker News says

1. amateurCoder5May 2023
   "JavaScript, The Good Parts" is not really relevant to modern JS. But Crockford's new book "How JavaScript Works" is basically the updated version. As an amateur coder I found it very useful, definitely worth reading.
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2. MathMonkeyManDec 2021
   Douglas Crockford has a sketch of a datetime library in his book, How JavaScript Works.

   I like it. Here's a summary.

   A datetime has three representations:

   - (real) number of milliseconds since the epoch,

   - string in some standard format (e.g. ISO 8601),

   - plain old object with the following properties: year, month (one-based), day, hour, minute, second (real), zone, week, weekday.

   Then there are four functions for generating datetimes and converting among the representations:

   - Date.now() -> Number

   - Date.object(Number | String, zone info? ...) -> Object

   - Date.string(Number | Object, format and/or zone info? ...) -> String

   - Date.number(Object | String, format and/or zone info? ...) -> Number

   You'd need the tz database under the hood and maybe exceptions for impossible or ambiguous datetimes.

   Aside from bundling the tz database, I don't see this library needing to be very large. And if it's small, it's not a big deal if it isn't standard.

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3. ZamicolDec 2024
   Hijacking for a random concern:

   I love JSON, but one of the technical problems we've ran into with JSON is that the spec forgot about all special characters.

   I actually noticed it when reading Douglas Crockford's 2018 book, "How JavaScript Works". The mistake is on page 22.9 where it states that there are 32 control characters. There are not 32 control characters. There are 33 7-bit ASCII control characters and 65 Unicode control characters. When thinking in terms of ASCII, everyone always remembers the first 32 and forgets the 33rd, `del`. I then went back and noticed that it was also wrong in the RFC and subsequent revisions. (JSON is defined to be UTF-8 and is thus Unicode.)

   Below is a RFC errata report just to point out the error for others.

   Errata ID: 7673 Date Reported: 2023-10-11

   Section 7 says:

   The representation of strings is similar to conventions used in the C family of programming languages. A string begins and ends with quotation marks. All Unicode characters may be placed within the quotation marks, except for the characters that MUST be escaped: quotation mark, reverse solidus, and the control characters (U+0000 through U+001F).

   It should say:

   The representation of strings is similar to conventions used in the C family of programming languages. A string begins and ends with quotation marks. All Unicode characters may be placed within the quotation marks, except for the characters that MUST be escaped: quotation mark, reverse solidus, and the control characters (U+0000 through U+001F, U+007F, and U+0080 through U+009F).

   Notes:

   There are 33 7-bit control characters, but the JSON RFC only listed 32 by omitting the inclusion of the last control character in the 7-bit ASCII range, 'del.' However, JSON is not limited to 7-bit ASCII; it is Unicode. Unicode encompasses 65 control characters from U+0080 to U+009F, totaling an additional 32 characters. The section that currently reads "U+0000 through U+001F" should include these additional control characters reading as "U+0000 through U+001F, U+007F, and U+0080 through U+009F"

   ---

   I've chosen `del` to be my favorite control character since so many engineers forget it. Someone needs to remember that poor little guy.

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4. MathMonkeyManMay 2024
   Crockford makes it work in his toy language in <https://www.amazon.com/How-JavaScript-Works-Douglas-Crockfor...>.
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5. gabrielsrokaJul 2020
   "How JavaScript Works" by Crockford was published in 2018.

   https://www.amazon.com/gp/aw/d/1949815005/ref=dbs_a_w_dp_194...

   https://youtu.be/8oGCyfautKo

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