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