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bit mask

A number whose 1 bits pick out the bits you care about, used with AND, OR or XOR to test, set, clear or flip them.

A mask m selects bit positions; x | m sets them, x & ~m clears them, x ^ m toggles them, and x & m tests them.

Examples

  • x & 0xFF keeps the low byte of x; x | (1 << 3) sets bit 3.

See also

XOR bitwise operation
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