如何在不使用getline的情况下在C ++中读取带空格的字符串

Question

my input file looks like this : S New York 25 76 49

i want to read them where S is a character and New York is either a string or a cstring and the other 3 are integers. My problem is reading in New York i cant use getline since the 3 integers come after it and not in a new line. What can i do?

Answer 1

I would suggest using Regular Expressions to parse the input. Added to the standard library in C++ 11 <regex> C++ reference

More details on wikipedia: Regular Expressions in C++

Answer 2

Your other option is simply to read a character at a time and as long as the character isalpha() or isspace() followed by another isalpha() , store the character in your string. For example:

#include <iostream>
#include <string>
#include <cctype>

using namespace std;

int main (void) {

    char c, last = 0;
    string s;

    while (cin.get(c)) {        /* read a character at a time */
        /* if last is alpha or (last is space and current is alpha) */
        if (last && (isalpha(last) || (isspace(last) && isalpha(c))))
            s.push_back(last);  /* add char to string */
        last = c;               /* set last to current */
    }

    cout << "'" << s << "'\n";
}

Example Use/Output

$ echo "S New York 25 76 49" | ./bin/cinget
'S New York'

It may not be as elegant as a regex, but you can always parse what you need simply by walking through each character of input and picking out what you need.