Title: 'Data Types' Description: 'Data is classified into data types that tell the compiler how the data is intended to be used.' Subjects:
- 'Code Foundations'
- 'Computer Science' Tags:
- 'Data Structures'
- 'Data Types'
- 'Types' CatalogContent:
- 'paths/code-foundations'
- 'paths/computer-science'
Data is foundational in programming and is classified into different types to indicate how it can be interpreted, compiled, and used in software. For the most part, data types are categorized into two groups: primitive or composite values.
Primitive data types are the building blocks for any variable or data structure in a program. They usually contain a single value such as a character, byte, or digit. A few examples of primitive types are listed below:
| Data Type | Description |
|---|---|
| Number | Includes -1, 0, 1, and 3.14(numbers with decimals treated as a separate type in some languages). |
| String | Sequences of characters surrounded by single quotes (''), double quotes (""), and/or backticks (``), depending on the language (e.g. "Codecademy is awesome! 🖥️⌨️" ). |
| Boolean | Holds a logical value of true or false. |
Composite data types can be composed of multiple of the same or different primitive data types, sometimes referred to as members, elements, or items. The following are examples of well known composite types:
| Data Type | Description |
|---|---|
| Array | Collections of values that are usually defined with [] brackets and referenced by index starting at 0. |
| Object | Groups of related data that are usually organized as property-value pairs. |
| Class | Templates for objects that may contain properties or methods. |
Data types have gone beyond just composites and primitives and include ones with unique qualities such as the following:
| Data Type | Description |
|---|---|
| Null | null or nil represents the absence of a value. |
| Undefined | Represents a value that has not yet been defined. |
| Function | Depending on the language, functions can be utilized as variables and arguments for other functions. |
| Void | Sets a function to have side effects but return no specific result. Common in C-based languages. |
| Complex Number | Type representation for complex numbers, sometimes with i or complex. |
The way that data types look and work may vary from one programming language to another: