Data Type string::size_type

Data Type string::size_type

Many C++ string member functions return a numeric value which is not of type int.  The member functions size() and length() return a value which has type string::size_type. This is an unsigned integer type. (An unsigned integer can never be negative.) Suppose I want to store the length in a variable. I must declare the variable. It is more precise to declare it as type string::size_type rather than int. Note that to use this data type, size_type must be preceded by the word string and two colons:

string state = "New York";

string city = "Cincinnati";

string::size_type num1, num2 ;

num1 = state.length();  num1 is 8 (the space is counted)

num2 = city.size();     num2 is 10

Notes:

• We are using the names of the strings--state and city--to indicate what string object [variable] the member function should act upon. [to whom the function belongs?]

• It is safest to use string::size_type when referring to string sizes or to positions in a string.