substr函数属于string类的一个函数
语法:
#include <string>
basic_string substr( size_type index, size_type num = npos );
用法:
substr()返回本字符串的一个子串,从index开始,长num个字符。如果没有指定,将是默认值 string::npos。这样,substr()函数将简单的返回从index开始的剩余的字符串。
举例:
string s("What we have here is a failure to communicate");
string sub = s.substr(21);
cout << "The original string is " << s << endl;
cout << "The substring is " << sub << endl;
输出:
The original string is What we have here is a failure to communicate
The substring is a failure to communicate