In computer science, data that has several parts can be divided into fields. For example, a computer may represent today's date as three distinct fields: the day, the month and the year.

Programming languages usually have a record data type to represent composite data types as a series of fields. An array of boolean values can be represented as a bit field.

Relational databases arrange data as sets of database records, also called rows. Each record consists of several fields; the fields of all records form the columns.

In object-oriented programming, field (also called data member) is the data encapsulated within a class or object. In the case of a regular field (also called instance variable), for each instance of the object there is an instance variable: for example, an Employee class has a Name field and there is one distinct name per employee. A static field (also called class variable) is one variable, which is shared by all instances.

Field modifiers in some object-oriented languages

Access Modifier	Field Modifier
public	final
private	static
protected	transient
	volatile

C# Field modifiers

Access Modifier	Field Modifier
public	readonly
private	static
protected	volatile
internal
protected internal

It must be noted that improper usage of modifiers of fields may result in unstable software behaviour.

See also

• key field
• record
• n-tuple
• attribute (computing)