int a=25; bool b=true; if b { cout<<a<<endl; } It gives an error during compilation and requires to put brackets (b) , although the condition is "monosyllabic". If the condition a!=1 && a!=2 question would not arise about brackets, but the condition is simple.
Try to write more detailed questions. To get an answer, explain what exactly you see the problem, how to reproduce it, what you want to get as a result, etc. Give an example that clearly demonstrates the problem. If the question can be reformulated according to the rules set out in the certificate , edit it .
You do not forget that the if clause can be written in one line. For example,
bool b = true; int x = 1; int *p = &x; if ( b ) * p += x; If we remove the brackets, we get
bool b = true; int x = 1; int *p = &x; if b * p += x; Which is completely unreadable.
The only thing you can put outside the brackets in the if clause is the constexpr keyword, which became possible with the advent of the C ++ standard 17.
You can find a simple example of using this syntax in my personal forum by clicking the New syntax of the if clause in the C ++ 17 standard and How to invert individual words in an object of the std :: string class
!(bool) , but this is also a compiler error. The more I think about the pros, the more I like the python. - Glebif not (bool) (if such a variant of events was added to the parser), or the negation sign standard in cpp ! . or implement the ifnot (bool) elseifnot (bool) elseif (bool) else branching operator, which would immediately take the negation of the condition. - Glebif not (condition) and if (!condition) different only in the spelling of the condition and the additional word. And reserved words in c ++ are enough. It's not worth it. - MrBinWell, as you read:
if b -- a; //??? this :
if(b) --a; if(b--) a; if (b -- a); Which of these expressions did the programmer mean? Not to mention other expressions where operator_characters can be found whose priority is higher, and then you need to read this expression from the beginning, then try to check some condition. It’s just that clever people wrote the language, and the syntax of the instructions was invented perfectly sensible.
Просто язык писали умные subjective assessment, not required by the question. Explain why the lack of a keyword ending condition is a smart move? And presence : in the python (based on your words) the decision is not smart people. As already mentioned above, in the absence of an opening bracket immediately after if, the end of the condition could be the first space or a newline character. Thus, without a condition ending keyword and with a short condition from one bool type variable, it would be possible to correctly determine the end of the condition, in my opinion. But this is not implemented, what are the reasons for this? - Glebif (b) --a; --> if b --a; if (b) --a; --> if b --a; if (b--) a; --> if b-- a; if (b -- a); --> if b--a; The thing is gaps. But in a particular case, I'm not talking about two arguments. Re-read the question, it is about the only variable of type bool. (and most often in my experience it is exactly such a construction bool isValue; if isValue {} ) - GlebSource: https://ru.stackoverflow.com/questions/927348/
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pythonyou have colons, and inluaandпаскальkeyword isthen. This is how the expression parser is implemented in order to accurately determine the position of the conditions and therefore the syntax requires a bracket. As a result, no contradictions and check easier. - Alex Krass