Primitive Data Type

The primitive data type is the basic building block of data. They hold one single value. They represent a string, number, or boolean.

Your key takeaways are:

• The basic building blocks of data are the primitives
• Primitives
  • hold a single value
  • representation for string, number, and boolean
• Each language has these building blocks

Study Notes

All data types are built off of the primitive types, so we’ll start with these.

Different Data Representations

What patterns do you see in the following table? Why are patterns important?

Patterns tell you a story. Patterns give you clues. Start watching for patterns.

How can patterns help you?

• problem-solving
• writing code
• building solutions for your customers

Data Types	Represents	Examples
boolean	literal truth-value state	true, false
char	a single character	‘A’, ‘z’, ‘&’, ‘!’, ‘_’, ‘1’
string	a grouping of characters	“Hello World”, “123”
byte	signed 8-bit two’s complement integer	84, -17
short	signed 16-bit two’s complement integer	872, -304
integer	signed 32-bit two’s complement integer	-69,723
long	signed 64-bit two’s complement integer	8,030,167,904,852
float	signed 32-bit floating-point value	-1826.001
double	signed 64-bit floating-point value	5.17 x10300

Patterns for the Data Types

• Numbers, strings, and booleans – these are your primitives
• Hold a single piece of information – one piece of data
• Memory size is dependent upon the data type
• Knowing the difference between data types will help you craft the right solution. For example, if the system you’re building only needs a float, but you use a double, you’re allocating more memory than needed.

Terminology

• Primitive Data Type
• Primitives

Simple Primitive Data Types

Notice the similarities between the different languages?

Language	Boolean	Char	String	byte, int, integer, short	long, float, double, real
PHP	✓		✓	✓	✓
JavaScript	✓		✓		✓
Ruby	✓		✓	✓	✓
Python	✓		✓	✓	✓
C	✓	✓	✓	✓	✓
C#	✓	✓	✓	✓	✓
Visual Basic	✓	✓	✓	✓	✓