Shortened arithmetical operators

The arithmetical operators can be used only for numeric and string data types.

These are examples of arithmetical operators for numeric types:

int i = 10;

i += 5;       // the same as   i = i + 5;
i -= 1;       // the same as   i = i - 1;
i *= 7;       // the same as   i = i * 7;
i /= 9;       // the same as   i = i / 9;

This is an example of an arithmetical operator for a string data type:

string s = "Hello";
s += " there."