Variables Variables are use to store values in mental memory. Suppose you want to use different values in your C++ program Data Types There are five basic data types associated with variables: int - integer: a whole number. float - floating point value: ie a number with a fractional part. double - a double-precision floating point value. char - a single character Input & Output In C++ standard input stream (cin) object is used to accept the input, WhileIn C++ the standard output stream (cout) command is used to display output on standard output Operators C++ have many built-in operators. Operators are symbols that tells the compiler to perform a specific operation. Without operators C++ programming language is incomplete. Constants Constants are fix values that a program don’t change, they are also known as literals. Constants are the values that can’t be change after their initialization.