getline() 和字符数组

Question

I am so sorry, I know this is a basic problem, but I couldn't find an answer anywhere. Maybe I didn't realize the key word. The problem is:

I want to get inputs from user, which will be stored in the check[] array, then I see through it to get if inputs are valid or invalid (valid if it is like SpaceSpace+0000[i=1-5] ).

    #include <iostream>
    #include <cstdio>
    #include <cstdlib>
    #include <cmath>
    #include <iomanip>
    #include <string>
    #include <cstring>    
    void main(){
    char check[7];
        for(i=0;i<7;i++){
                    check[i]='1';
            };
        //int check[4];
        cin.getline(check,4);
          bool cond=1;
            for(i=0;i<7;i++){
                    cout<<check[i];
            };
          }

But when I print ( cout ) the array, I realized this: Input is 33 , array[] is " 33 ' Space '1111" , my question here is what does the space in output mean and how could I deal with it(ignore, remove or anything).

Answer 1

The problem is that istream::getline reads the input, and then write a null-terminated byte string to your array.

What you see as a "space" is simply the null-terminator '\\0' .

If you want to read raw unformated characters, use a loop to read one character at a time instead (checking for eof and newline):

char ch;

// Read up to four character, or until there's an error or end-of-file,
// or until you get a newline
for (unsigned i = 0; i < 4 && cin.get(ch) && ch != '\n'; ++i)
{
    check[i] = ch;
}