12. Integers

Using Natural Numbers

Integer Types
Integers are used to store natural numbers are 1,2,3.
Go has 8 types on integers
 int8, int16, int32, and int64, and corresponding unsigned versions uint8, uint16, uint32, and uint64.
unsigned integers can store positive numbers only.
8,16,32 and 64 represents how many bits are used to store value.
Bits
Signed
Unsigned
8
–128 to 127
0 to 255
16
–32,768 to 32,767
0 to 65535
32
–2,147,483,648 to 2,147,483,647
0 to 4,294,967,295
64
–9,223,372,036,854,775,808 to 9,223,372,036,854,775,807
0 to 18,446,744,073,709,551,615
Declaring Integers
Integers are declared using one of the 3 ways:
main.go
var j int32 = 20
var i int = 10
var i = 10

i := 10
var k int
If we are not specifying type like in 2nd and 3rd declaration, it will default to int
Zero value for integer is 0
Always use short declaration way when assigning initial value. If you wish to initialize a variable to its zero value, use var declaration.
Using Test Driven Development for integers
Learn how to do test driven development when using integers from Chris
quii/learn-go-with-tests
Learn Go with test-driven development. Contribute to quii/learn-go-with-tests development by creating an account on GitHub.
github.com
​

11. Constants

12. Floats

Last updated 1 year ago

Bits	Signed	Unsigned
8	–128 to 127	0 to 255
16	–32,768 to 32,767	0 to 65535
32	–2,147,483,648 to 2,147,483,647	0 to 4,294,967,295
64	–9,223,372,036,854,775,808 to 9,223,372,036,854,775,807	0 to 18,446,744,073,709,551,615