I've seen code in my workplace using parseInt to round JS Number. Made me cringe coming from system programing but I didn't see the danger.
It's sad the only way to prevent such a bad code in production is to use transpilers.
this post was submitted on 05 May 2025
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Good old JS, because exceptions are a sin.
looks functional to me. Its a pure function, right?
What language is that so I can avoid it.
We all know what it is.
lol it’s js of course
I know this is for fun, but as general advice to the homies, if a language or system is doing something you didn't expect, make sure to look at the documentation
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/parseInt
This will save a lot of time and headaches
oh god the reason is even stupider then I expected
Because large numbers use the
echaracter in their string representation (e.g.,6.022e23for 6.022 × 1023), usingparseIntto truncate numbers will produce unexpected results when used on very large or very small numbers.parseIntshould not be used as a substitute forMath.trunc().
Holy fuck that is long. When the documentation for the integer parsing function is 10 pages long, there's something seriously wrong with the language
Is it? I've seen longer articles for C# and not as many complaints about it.
Probably not an article about integer parsing, though. If the docs are that long, then because Microsoft does have a tendency to be overly verbose for things they think you need, just to have no docs for the stuff you actually need.
For reference here's the relevant rust docs.
https://en.wikipedia.org/wiki/Principle_of_least_astonishment
...and of course JS made it into the examples, how could it not:
A programming language's standard library usually provides a function similar to the pseudocode ParseInteger(string, radix), which creates a machine-readable integer from a string of human-readable digits. The radix conventionally defaults to 10, meaning the string is interpreted as decimal (base 10). This function usually supports other bases, like binary (base 2) and octal (base 8), but only when they are specified explicitly. In a departure from this convention, JavaScript originally defaulted to base 8 for strings beginning with "0", causing developer confusion and software bugs. This was discouraged in ECMAScript 3 and dropped in ECMAScript 5.
Okay but this documentation is obviously wrong from the first sentence
The parseInt() function parses a string argument and returns an integer of the specified radix
Integers don't have radices. It should read:
The parseInt() function parses a string argument representing an integer of the specified radix and returns that integer.
~~Either way, I still don't understand the behaviour in the image.~~ nvm, thanks [email protected]
I'd advise to always look into the corresponding documentation before using something from any library.
But I'm too busy being confused by the behaviors of libraries I previously didn't read the documentation for, to read the documentation for every new library I adopt.
(This is sarcasm...mostly.)
I'll go with 5 hours of debugging, thank you very much!
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