+ 2

is there a way to avoid crashes if a character is emtered in an int locaion?

I am tring some small projects for. Ow to get warmed up. I have an int variable but by accident sometimes a character is entered. Is there a way to avoid that?

26th Jul 2017, 9:49 PM
Dustin
14 Answers
+ 9
@Immortal: Indeed!
26th Jul 2017, 10:20 PM
jay
jay - avatar
+ 9
@Martin: Faith meant something like this: https://code.sololearn.com/cPGkBUJ2B2GY/?ref=app as for putting floats into ints.. where is the problem exactly? 😊
27th Jul 2017, 1:40 AM
jay
jay - avatar
+ 9
@aklex. there is also stringstreams
27th Jul 2017, 2:05 AM
jay
jay - avatar
+ 9
@martin.. is that a problem though? it wont crash the program. that is just user error
27th Jul 2017, 2:06 AM
jay
jay - avatar
+ 8
int userInput; cin >> userInput; if(!cin) { cin.ignore(); cin.clear(); cout << "that was not a number\n"; } something like this 'should' work faiths answer is probably better as it will get you used to error handling
26th Jul 2017, 10:09 PM
jay
jay - avatar
+ 8
just put the try catch in a loop. it wont end the program when you raise/throw the error as it will be handled in catch.. (hint: you will need to add clear and ignore in the catch bit 😊 i will update the code to show this
27th Jul 2017, 1:47 AM
jay
jay - avatar
+ 8
updated
27th Jul 2017, 1:56 AM
jay
jay - avatar
+ 7
All languages have the built in abilities to raise and solve errors. Python is: try: except: finally: C++ is try{} catch{} finally{}
27th Jul 2017, 2:03 AM
πŸ‘‘ Prometheus πŸ‡ΈπŸ‡¬
πŸ‘‘ Prometheus πŸ‡ΈπŸ‡¬ - avatar
+ 7
i see! thanks!
27th Jul 2017, 2:25 AM
jay
jay - avatar
+ 7
https://code.sololearn.com/cmN6QtO8dCCM/?ref=app hows this? pretty sure it ticks all your boxes.. note: pretty much exactly what aklex did πŸ˜€
27th Jul 2017, 3:21 AM
jay
jay - avatar
+ 6
? but it doesnt need to be edited for a second input. i will try it on pc... try inputing this into the box 837 244 123.44 384 as it is a loop, it will continue prompting the user for the correct input. on here a single incorrect entry will be reentered forever or until timeout. on the pc it works as expected 837 244 error 123.44 error 384 correct. program ends
27th Jul 2017, 4:02 AM
jay
jay - avatar
+ 4
Safe way of doing it, though you will get an exception if the input is too large, so you also have to use a try statement on stoi or check if it's too big: #include <cctype> bool verifyInput(const std::string& input) { for (auto& i : input) { //check if digit if (!std::isdigit(i)) return false; //not a digit, return false } //input is numbers only return true; } int main() { std::string input; std::cin >> input; if (verifyInput(input)) { //input was valid, now we convert it to int int goodinput = std::stoi(input); } }
27th Jul 2017, 2:28 AM
aklex
aklex - avatar
+ 4
@Martin Javascript has try catch 😜 @- I think a better approach to checking if something is a float would just be to take the input as a float instead of a string. Then, subtract it by the integer value, if it's equal to 0.0, the input can be taken as an integer then the stream can be cleared of all extra numbers. Something like this: https://code.sololearn.com/cebDG8afXwM0/?ref=app
27th Jul 2017, 2:29 PM
Rrestoring faith
Rrestoring faith - avatar