How do I set the number of digits to be entered for input and display an error message if this is not met?

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Ahsan 2014-10-14

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评论： Ahsan 2014-10-15

I want the the user to enter a date and year. How do I make it so that four digits must be entered for the year, and that two digits must be entered for the date (leading zeros are okay)? I know that I can use an if statement with the error function, but is there a function to set the number of characters for input that I can use with the if statement?

Thanks

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Geoff Hayes 2014-10-15

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You could use length to check to see if the user has entered six characters, and raise an error if this is not true

 dateString = input('Enter a date and year (YYYYMM): ','s');
 if length(dateString)~=6
     error('invalid date string (not enough characters)');
 end

To check to see if only numeric characters have been entered, then use regexp as

 dateString = input('Enter a date and year (YYYYMM): ','s');
 if length(dateString)~=6
     error('invalid date string (not enough characters)');
 elseif ~isempty(regexp(dateString,'\D'))
     error('invalid date string (non-numeric characters)');
 end