Note: There is only one substring operation function in C++: s.substr(); there is no s.substring() function, s.substring() is in java.
There are operations on substrings in both Java and C++, substr() in C++ and substring() in Java. The usage of the two is slightly different.
1. First of all, for the case of only one parameter:
s.substr(start) 和 s.substring(start)
Both represent the substring from the start position to the end.
2. For the case of two parameters:
there is a difference between the two:
C++: substr(start, len),The starting position of the first parameter, the second parameter is the length of the substring
Java: substring(start, end)，The first parameter is the starting position, the second parameter is the ending position
3. You can refer to the following example code:
C++:
string s = "HelloWorld";
cout << s.substr(4, 4) << endl; // oWor
cout << s.substr(4) << endl; // oWorld
Java:
String s = "HelloWorld";
System.out.println(s.substring(4, 8)); // oWor
System.out.println(s.substring(4)); // oWorld
Reprinted from: The difference between C++ substr() and Java substring()