# 12. Integers

Using Natural Numbers

- 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 |

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.

Learn how to do test driven development when using integers from Chris

Last modified 3yr ago