Numbers

Go has several numeric types so you can pick the right size and kind for your data.

Integer types

Signed and unsigned integers come in different sizes.

var a int8 = 127
var b int32 = 100000
var c uint = 42 // unsigned, no negatives
fmt.Println(a, b, c)

The plain int is the most common and matches the platform word size.

Floating point

var x float32 = 3.14
var y float64 = 2.718281828
fmt.Println(x, y)

float64 is the default for decimals and offers more precision.

Converting

Conversions must be explicit between numeric types.

i := 10
f := float64(i) / 3.0
fmt.Printf("%.2f\n", f) // 3.33

The math package

The math package provides common functions and constants.

import "math"

fmt.Println(math.Sqrt(16))   // 4
fmt.Println(math.Max(3, 9))  // 9
fmt.Println(math.Pi)         // 3.141592653589793
fmt.Println(math.Floor(2.7)) // 2