The compiler or interpreter does that for you. There’s no point in these “gotcha’s”. They are cute brain teasers that belong on those useless “are you a programmer” quizzes you find on random meme websites, not an exam.
In the error shown a compiler would be just fine and run as usual but the person programming it would be expecting a different result so a compiler wouldn’t do this for you since it’s a logical error and not a syntax error.
If it’s a statically typed language and
x
is of typeDate
, it’s for sure throw a type error when trying to assign a string to it. If it had autoboxing / auto type conversion fromString
toDate
, length could return a number or a string.If this were Javascript on NodeJS, it would fail at
print(x)
because that doesn’t exist in JS. If it were Python it would fail atx.length
because that has to belen(x)
. And so on.If this were all to pass, at the latest at runtime, when the programmer sees the output “6”, they would know something’s up.
As I said, cute, but worthless test.