How can we validate input in C++?
Let me elaborate my question: Example I want to show an error saying "Name only contains alphabets" when the user types any number or any other character in the name field.
You can use regular expressions in c++ to validate input as per specific criteria.
You can learn about regex here :
https://www.sololearn.com/learn/9704/?ref=app
You need to include the 'regex' header in your code to be able to use regex statements :
#include <regex>
For your case, the regex will be declared like this :
regex pattern("[A-Za-z]+");
Then you can use regex_match for checking if a string satisfies your requirement :
string str = "Hello";
if(regex_match(str,pattern))
{ cout<<"Good!"; }
else cout<<"Try again";
To use the regex library, you need to ensure that your compiler supports c++11 (atleast). Try executing the following statement, and let me know what the output was :
cout<<__cplusplus<<endl;
[email protected] That version is no good in 2018. You need to enable the flag '-std=c++11' for your compiler, or if possible, switch to Code::Blocks 17.12, as hinanawi mentioned.
