Thread: Help with 2-D character array

Code:

...
stdID[1000];   //1-D array that stores a 8-digi Student ID
StdName[1000][50];   //2-D array that stores Student Name
...

Is there any ways that enable me to check whether user enters a correct information for each array. That is, warns user if he enters character in stdID field? Moreover, each student ID must be formed by 8-digi, so how can I check the user inputs if he really keys in complete 8 digi? Is it checking the position of '\0'?

One more, how can I find the end of the array, that is the amount of coloums of an array that have been used. (You may want to know why I want to know this...It's because, I want to continue to add some more data to an existing array that has been sotred some other data before.)

Sorry to ask such stupid question yet I'm new in C++. Thx for anyone!