Data Types

The data the computer uses are of many different types.
Computer must be told about the data type of each variable or constant.

Numeric Data

• Includes all types of numbers. The subtypes of numeric data type are Integer and Real
• Integers are whole numbers
• Real numbers or floating point numbers are whole numbers plus decimal parts
• A real number can be represented in scientific notation such as 2.5E5 or 3.2E-3. No commas are used.

Character Data

• The character data set consists of all single digit numbers, letters and special characters, available to the computer – placed within quotation marks.
• An uppercase letter is considered different from a lowercase letter.
• When more than one character is put together, the computer considers this item as a string.
• Character and string data are compared and arranged in alphabetical order.
• The computer gives each character a number (ASCII Codes). The numbers are compared to see which is larger and are then arranged in ascending order.
• Upper case letters are given a smaller value than a lowercase letter.

Logical Data

• Consists of only two values – true and false.
• They are used in making yes-or-no decisions.
• For example, to check the credit record.