Javascript what does the

 

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  • Using bitwise OR 0 to floor a number 5 answers

    • It's a bitwise operator... to quote this page:

    Bitwise operators treat their operands as a sequence of 32 bits (zeroes and ones), rather than as decimal, hexadecimal, or octal numbers. For example, the decimal number nine has a binary representation of 1001. Bitwise operators perform their operations on such binary representations, but they return standard JavaScript numerical values.

    what happens, is that the operator treats the number as a 32 bit integer; so 5.123 is treated as: 

     0000 0000 0000 0000 0000 0000 0000 0101

    (the decimal part is thrown out) and 0 is treated as 

     0000 0000 0000 0000 0000 0000 0000 0000

    then the OR function compares the two, and writes a 1 if either number has a 1. So using the bitwise Or with a decimal number and zeeo is essentially a way to discard the decimal part and retain the integer part.

    Your other example with two is: 

     0000 0000 0000 0000 0000 0000 0000 0101 (5)
 0000 0000 0000 0000 0000 0000 0000 0010 (2)
 --------------------------------------- ORed
 0000 0000 0000 0000 0000 0000 0000 0111 (7)

    and the example with 4: 

     0000 0000 0000 0000 0000 0000 0000 0101 (5)
 0000 0000 0000 0000 0000 0000 0000 0100 (4)
 --------------------------------------- ORed
 0000 0000 0000 0000 0000 0000 0000 0101 (5)

    You can use it to convert to discard the decimal part of a number - see Using bitwise OR 0 to floor a number

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