I’d argue that there are some valid use cases for “5” and 5 to be equal. For example, if you take user input where on an admin screen for a user ID or username, you don’t know if the type is a string or number. Another common example is when you don’t have a known encoding for a packet yet, so you treat it as a binary string. In these cases, it’s easier to grok, as a human what is expected.
If you want to compare input to an int, you should be verifying the input is a valid int before comparing it.
Just hoping the language will do the right thing is a great way to inadvertently allow exploits in your service
Accepting both a numerical user id and a username string is a very valid scenario. However, I believe you should handle that by explicitly trying to parse it as a number, not hoping that automatic coercion will do the right thing. It's just a footgun waiting to go off.
"5" == 5
"⑤" == 5
"⑸" == 5
"⁵" == 5
"𝟝" == 5
"𝟓" == 5
"𝟻" == 5
"V" == 5
"Ⅴ" == 5
"𝍸" == 5 # https://unicode-table.com/en/1D378/
"𐄋" == 5 # https://unicode-table.com/en/1010B/
"৫" == 5 # https://unicode-table.com/en/09EB/
This is why many people recommend questioning the use of basic or naked types. Details vary between the language, but this should be a type UserID with a UserID::from(String) and maybe a UserID::from_symbolic_name(String) and everything but some edge code should work on UserIDs. This makes code easier to read, too.
People usually understand the difference between "cat" and a cat.
So "5" + 1 is 6, just as 5 + 1 is 6.
Perl uses .
Oracle SQL uses ||
Microsoft SQL and VBA use &
C obviously doesn't use +.
Neither does Pascal.
Power Query doesn't.Nope, Microsoft SQL uses +.
* https://docs.microsoft.com/en-us/sql/t-sql/language-elements...
* https://i.imgur.com/7z81o8t.png
* https://i.imgur.com/VDR9qer.png
> C obviously doesn't use +.
But C++ does for std::string.
> Neither does Pascal.
Original Pascal didn't, but I think most modern Pascals do (e.g. Object Pascal known from Delphi).
I was referring to Access.
>Original Pascal didn't, but I think most modern Pascals do
I'm pretty sure concat() was used in THINK and Metrowerks Pascal in the 90s.
VBA (and VB in general) overloads "+" for strings in addition to providing "&", the difference being mostly in what gets converted to what in various situations: https://docs.microsoft.com/en-us/office/vba/language/referen...
Python and Ruby even overload *, for the dubiously useful construction:
"hello" * 3 == "hellohellohello"
For the most part, the developers in those spaces seem to know the pitfalls and how to avoid them.