Data Types in C++

• Data may be variables or constants. They must be declared before they can be used. Declarations have the following form...

• <data type> indentifier_list;e.g.,
  int x, y; //declares identifiers x and y as integers
  const float PI = 3.14; //declares and initializes a float constant named PI

• Identifiers can be upto 127 characters long, must begin with a letter, must consist of letters, numbers, and underscores only, and must not use

          reserved words

• C++ Supports the following simple types of data:

Simple Data Types


• char

  The smallest data type, usually require 1 byte of storage. Assume single character values.

• int

  These data types assume integer values. There are three types of integers - long , int, short. Long integers require the largest amount of storage of the three, and short integers require the least amount of storage. Many compilers treat short integers and integers as the same, whereas some other compilers do not distinguish between long integers and integers.

• enum

  They are stored internally as integer values, but are used in programs to represent categorical data. They are not used in arithmetic operations.

• float

  Assume rational number values i.e.,the number values have an integer part and a fractional part. They usually require the same amount of storage as integers

• double

  Assume rational number values, however, they provide a higher degree of precision than float data types. They exist in two forms: long double, and double. Long double data types provide a higher degree of precision than double data types, however they also require more storage.

• In addition C++ supports complex types of data such as arrays, structs, unions, and classes. C++ also supports two other special data types - pointers and references. These data types will be discussed later

Back to Previous Page