One of the more important aspects of programming, data types describe the nature of a value or data that is contained in a variable or even a constant. Variables can have different and changing values, while constants will be assigned a value that doesn’t change. There are several different data types and they generally fall into two different categories. They can be either scalar or compound.
Technipages Explains Data Type
The former means that the variable (or constant) holds a single value, while the latter means that multiple values are held in the same unit. New programmers learn to work first with scalar data types – they include things like integers, strings, dates and Booleans.
An example of compound variables would be arrays, where multiple sets of data are held in the same file. Each data type, no matter what it ends up being, defines what sort of information can be held in the variable or constant.
In the case of integers and strings, for example, variables or constants can only contain either numbers or letters. When a variable is set up, for example, it is assigned a datatype that then determines what can be in it. This can’t be changed later on, although the content of a variable CAN be changed.
A secondary meaning of the term relates to databases – data type is a classification that is given to a data field, and then determines what information or data can be entered into it when records are added.
Common Uses of Data Type
- Data types determine the sort of information that can be entered into a field of a database when records are added.
- Setting a variable up as a certain data type means that whatever value is assigned to it later, it must be compatible with the rules imposed by the datatype – integers can’t contain letters, while Booleans can’t contain anything other than Yes and No values.
- The purpose of data types in high-level programming languages is to show the program what sort of content it can expect – they can also be used to test whether a certain variable contains a type of content (like a special character in a number type).
Common Misuses of Data Type
- Data types are names for fields in databases, into which info for records is entered.