Data Types & Null Values

Basic Types

Go comes with a couple of built-in basic types:

Type	Description	Value
integer	A number without decimal places	5, 10, 12
float64	A number with decimal places	5.2, 10.5, 35.69
string	A text value created with double quotes or backticks	"Hello World!" or `Hi there!`
bool	Conditional value	true, false

But there also are some noteworthy "niche" basic types which you'll typically not need that often but which you should still know about:

• uint => An unsigned integer which means a strictly non-negative integer (e.g., 0, 10, 255 etc)

• int32 => A 32-bit signed integer, which is an integer with a specific range from -2,147,483,648 to 2,147,483,647 (e.g., -1234567890, 1234567890)

• rune => An alias for int32, represents a Unicode code point (i.e., a single character), and is used when dealing with Unicode characters (e.g., 'a', 'ñ', '世')

• uint32 => A 32-bit unsigned integer, an integer that can represent values from 0 to 4,294,967,295

• int64 => A 64-bit signed integer, an integer that can represent a larger range of values, specifically from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807

• There also are more types like int8 or uint8 which work in the same way (=> integer with smaller number range)

Null Values

All Go value types come with a so-called "null value" which is the value stored in a variable if no other value is explicitly set.

For example, the following int variable would have a default value of 0 (because 0 is the null value of int, int32 etc):

var age int // age is 0

Here's a list of the null values for the different types:

• int => 0

• float64 => 0.0

• string => "" (i.e., an empty string)

• bool => false