Different uses of the PHP median operation (bitwise and, bit, or)

What is the role of bitwise-and-bitwise, or in the development process of PHP? /** * 1. Permission application * What permissions you have, add up the values corresponding to these permissions * For example: Moderator has permission (add, delete, modify, query), the moderator's permission value is stored as 15 (8+4+2+1) * then "sum of permission values" is compared to "actual permission value" * The result is true and has permissions * result is false then no permission * * Note: The permission value must be 2 of the N-square, starting from 0 times, 31 times is 2147483648 * 32 times is 4294967296, has exceeded the usual int (10) maximum storage 4294967295, so must pay attention to the number of permissions (<31) * Of course, if the storage format is bitint or varchar, etc. can store longer numbers, then the number of permissions can continue to increase */ $permission = 15; 1+2+4+8 has full privileges $permissions = Array ( 8 = ' Increase ', 4 = ' Delete ', 2 = ' Modify ', 1 = ' query ' ); foreach ($permissions as $key = = $val) { if ($key & $permission) { Echo ' I have '. $val. ' The Power '; } } Copy Code Waiting to be added Copy Code

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