检查字符串是否采用“坐标/坐标”格式

Question

I would love to know how to check if a string has the format of two coordinates, like:

(signed int x,signed int y)

I've already found some answers via search but I don't quite get them yet (just started with c++) and I'm asking for a simple solution or hint how to check this. Thanks!

Answer 1

I would use this one (some simpler might exist):

^\(\-{0,1}\d*,\-{0,1}\d*\)

Which is:

^\(       start by a parenthesis
\-{0,1}   0 or 1 "-"
\d*       any digit
,         ","

and repeat.

Answer 2

I'm assuming you need to take specifically a string as input. I'd check each value of the string.

string str;
// something happens to str, to make it a coordinate
int n = 0;
int m = 48;
bool isANumber;
bool hasASlash = false;
while ((n < str.length()) and isANumber) {
    isANumber = false;
    if (str.at(n) == '/') {
        hasASlash = true; // this means there is a slash somewhere in it
    }
    while ((m <= 57) and !isANumber) {
        // makes sure the character is a number or slash
        if ((str.at(n) == m) or (str.at(n) == '/')) isANumber = true;
        m++;
    }
    m = 48;
    n++;
}
if (hasASlash and isANumber) {
    // the string is in the right format
}

Please correct me if I've done something wrong...