Exam | Extension for Concordion BDD Framework

To construct an array with named dimnames, pass a named list as the dimnames argument of matrix or array:

There is a chunk method in laravel for queuing large data. You can chunk the data and try importing datas Here is the link for reference: here

I hope this link will help you. Here is what documentation says about it.

If you need to work with thousands of database records, consider using the chunk method provided by the DB facade. This method retrieves a small chunk of results at a time and feeds each chunk into a closure for processing. For example, let's retrieve the entire users table in chunks of 100 records at a time:

With apply, use MARGIN = 1, to loop over the rows on the numeric columns, sort, get the head/tail depending on decreasing = TRUE/FALSE and return with the mean in base R

the exam answer was that the function was returning a dangling reference

Correct.

but (...) does not present any undefined behaviour of the program.

What makes you think so? Undefined behaviour doesn't mean "program doesn't work correctly" or "program crashes". Undefined behaviour means exactly what it says: the behaviour is not defined by the standard. In fact it may work "correctly" (whatever that means), the standard doesn't prohibit it. That's why it is so dangerous. Because maybe in your test it works correctly, because of the hardware, OS, specific compiler, some other assumptions that take place. But the problem is that it is not guaranteed to work correctly. If you change machine, OS, a compiler (even switch optimization settings), a code slightly or even compile it two days later it may behave weirdly, in an (ekhm) undefined way.

In general there is no way to know whether a program behaves correctly or not, if UB is present. You are trying to analyze the situation by thinking about l-values, r-values, allocations, etc. while the reality is that when UB is present the entire program is meaningless. You just waste time.

Do not write UB code. Regardless of whether it seems that it works or not.

It does not default to zero. The sample answer is wrong. Undefined behaviour is undefined; the value may be 0, it may be 100. Accessing it may cause a seg fault, or cause your computer to be formatted.

As to why it's not an error, it's because C++ is not required to do bounds checking on arrays. You could use a vector and use the at function, which throws exceptions if you go outside the bounds, but arrays do not.

You're basically correct. Prefix function application (what you called the "space operator") binds more tightly than any infix operator does. And for completeness, the way to fix the error is to do (reverse . take 3) [1 .. 10] or reverse . take 3 $ [1 .. 10] instead.

Instead of using just: input('What you want to ask'), use int(input('What you want to ask'))

As has been mentioned in the comments, the "problem" is the data type, not the expression.

If we take the below example:

You can use reduce to extract the last value from Map and then collect them using toMap into LinkedHashMap to save the insertion order