Zero values
Variables declared without an explicit initial value are given their zero value.
The zero value is:
0
for numeric types,false
for the boolean type, and""
(the empty string) for strings.
zero.go
package main
import "fmt"
func main() {
var i int
var f float64
var b bool
var s string
fmt.Printf("%v %v %v %q\n", i, f, b, s)
}