c++operatorsbit

<< operator in C++?


I am new to C++, what's the exact meaning for the << in statement below, Thanks.

if (Val & (0x0001 << 0))
{}
else
{}

Solution

  • It is a shift-left operation. If you have:

    a << b
    

    where a and b are integral types (char, short, long, etc.), then the bits in a are shifted left b places with zeroes filling in on the right. In other words, a is multiplied by 2^b.

    Example:

    12 << 3
    
    12 (decimal) = 00001100 (binary)
    

    shift left 3 places:

    00001100 becomes 01100000 
    

    which is 96 (which is 12 * 8 or 12 * 2^3)