Is it possible to use cin.getline() without denoting an array size?
That is, with the following pseudo-code:
char array[15];
cin.getline(array,'.'); // '.' Is the delimiter.
Will this work?
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Lightness Races in Orbit
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Harjyot Singh
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2even i assume that you are dealing with c++, you should generally tag as well your questions with the language you are dealing with. – user1767754 Feb 10 '14 at 08:27
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Yes: join the 20th (!) century:
std::string str;
std::getline(std::cin, str, '.');
Lightness Races in Orbit
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What will happen:
This will compile and run, but your delimiter won't work and you will get undefined behaviour. Furthermore you will loose 1) exception handling, when the array size is not given. (When the input is higher than the size, you will get a 2) "stack corrupted" run-time error). With the size given, the rest length will be cut.
1) Exception Handling:
If you define a size for your array, it will substring the user-input, so that you are not writing more characters into your string than it has room allocated. (i.e. more than 15) (This type of substring will only be available, when you define your size.
2) Stack Corrupted Error:
Without defining the size, you will get a "stack corrupted error" which means, that you try to write more than you have allocated.
3) Running your code: Your code will run, but you will have undefined behaviour at runtime.
http://coliru.stacked-crooked.com/a/64b881aa9f70c21d
Doing it the right way: As "lightnes races in orbit" already mentioned, this is the way to go:
std::string str;
std::getline(std::cin, str, '.');
more to read: http://www.cplusplus.com/reference/string/string/getline/
user1767754
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`Furthermore you will loose [sic] exception handling, when the array size is not given` What sort of exception handling is lost? – Lightness Races in Orbit Feb 10 '14 at 08:57
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`When the input is higher than the size, you will get a "stack corrupted" run-time error` Only if you're lucky. More often than that, you will simply mangle/corrupt some other object. – Lightness Races in Orbit Feb 10 '14 at 08:58
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`This will compile and run` Assuming you're talking about `char array[]`, [no, it won't](http://coliru.stacked-crooked.com/a/e90dbab044bc9dc8). – Lightness Races in Orbit Feb 10 '14 at 08:58
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His question was, if it will work, i was just describing the behaviour of his lines. But i completely looked on it from the perspective of "what will happen when" instead of "how to read user input" – user1767754 Feb 10 '14 at 12:45
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And I'm questioning the accuracy of your answer. I broke my problems with it down into individual concerns. – Lightness Races in Orbit Feb 10 '14 at 12:47
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i tried to give a better explanation now, if i am wrong at a point, please feel free to correct me. – user1767754 Feb 10 '14 at 13:07
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I already did. Please read my first three comments, and address them. – Lightness Races in Orbit Feb 10 '14 at 13:27
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I saw your edit and I'm telling you that my queries to you stand. Will you address them? Or continue to ignore them... – Lightness Races in Orbit Feb 10 '14 at 14:47
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You can just edit them, and i may accept them, and like all of your comments. – user1767754 Feb 10 '14 at 14:49
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Thank you for clearing my doubts. I'm sorry I'm not affluent with the correct declarations you've shown above, bein a student, the resource books provided are too outdated I think. I apologize for my naivety. – Harjyot Singh Feb 10 '14 at 19:44