golang strange syntax errors

file_Read.go

package main
import "fmt"
import "os"

func main() {
        
        file, _ := os.Open("list.txt", os.O_RDWR, 0644)
        var b [40000] byte 
        file.Read(&b)
        fmt.Print(len(&b))
        fmt.Print("\n")
        file.Close()
        os.Exit(0)

}

output

40000


=========
while the file size for list.txt is 1562