Most programming tasks involve manipulating data. In this chapter, we will: Describe how to input and output data, present the notion of a variable for holding data, introduce the central notions of “Type” and “Type Safety”. | Chapter 3 Objects, types, and values Bjarne Stroustrup Abstract Most programming tasks involve manipulating data. Today, we will: describe how to input and output data present the notion of a variable for holding data introduce the central notions of “Type” and “Type Safety” Stroustrup/Programming/2015 Overview Strings and string I/O Integers and integer I/O Types and objects Type safety Stroustrup/Programming/2015 Input and output // read first name: #include "" // our course header int main() { cout > first_name; cout Stroustrup/Programming/2015 Overview Strings and string I/O Integers and integer I/O Types and objects Type safety Stroustrup/Programming/2015 Input and output // read first name: #include "" // our course header int main() { cout > first_name; cout Stroustrup/Programming/2015 Source files "" is the header for our course Interfaces to libraries (declarations) #include "" My code My data (definitions) : : Stroustrup/Programming/2015 Input and type We read into a variable Here, first_name A variable has a type Here, string The type of a variable determines what operations we can do on it Here, cin>>first_name; reads characters until a whitespace character is seen (“a word”) White space: space, tab, newline, Stroustrup/Programming/2015 String input // read first and second name: int main() { cout > first >> second; // read two strings string name = first + ' ' + second; // concatenate strings // separated by a space cout << "Hello, "<< name << '\n'; } // I left out the #include "" to save space and // reduce distraction // Don’t forget it in real code
