Golang 中的位掩码和按位运算 |

icz*_*cza 7

111iota

role

var roles byte = isAdmin | canSeeFinancials | canSeeEurope

1001role

为了轻松理解这些位，让我们打印二进制表示：

fmt.Printf("isAdmin          %08b\n", isAdmin)
fmt.Printf("canSeeFinancials %08b\n", canSeeFinancials)
fmt.Printf("canSeeEurope     %08b\n", canSeeEurope)
fmt.Printf("-------------------------\n")
fmt.Printf("roles            %08b\n", roles)

这将输出：

isAdmin          00000001
canSeeFinancials 00000100
canSeeEurope     00100000
-------------------------
roles            00100101

roles11

0011

表达方式：

isAdmin & roles

isAdmin11roles1rolesisAdminisAdmin00

再次可视化这些位：

fmt.Printf("roles            %08b\n", roles)
fmt.Printf("isAdmin          %08b\n", isAdmin)
fmt.Printf("-------------------------\n")
fmt.Printf("isAdmin & roles  %08b\n", isAdmin&roles)

输出：

roles            00100101
isAdmin          00000001
-------------------------
isAdmin & roles  00000001

试试Go Playground上的例子。

所以表达式：

isAdmin & roles == isAdmin

truerolesisAdminfalse

无遮罩：

roles == isAdmin

truerolesisAdminisAdminisAdmin