Because...

Decimal  Binary
  123    01111011
    4    00000100 
         ========
         00000000 when ANDed together

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The answer comes from ANDing the bits in the columns together. Bit 2 (third from the right) has a decimal value of 4 (because 22 = 4).

Is that any clearer?

In reply to Re^3: Bitwise and operator question by FunkyMonk
in thread Bitwise and operator question by Severy

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