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.
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