Unsigned Integer in Javascript

Douglas Crockford believes that bitwise operators is one of the bad parts of javascript:

In Java, the bitwise operators work with integers. JavaScript doesn't have integers. It only has double precision floating-point numbers. So, the bitwise operators convert their number operands into integers, do their business, and then convert them back. In most languages, these operators are very close to the hardware and very fast. In JavaScript, they are very far from the hardware and very slow. JavaScript is rarely used for doing bit manipulation.

-- Douglas Crockford in "JavaScript: The Good Parts", Appendix B, Bitwise Operators (emphasis added)

Are you sure that bitwise operators really speed up your logic?

document.write( (1 << 31) +"<br/>");

The << operator is defined as working on signed 32-bit integers (converted from the native Number storage of double-precision float). So 1<<31 must result in a negative number.

The only JavaScript operator that works using unsigned 32-bit integers is >>>. You can exploit this to convert a signed-integer-in-Number you've been working on with the other bitwise operators to an unsigned-integer-in-Number:

document.write(( (1<<31)>>>0 )+'<br />');

Meanwhile:

document.write( (1 << 32) +"<br/>");

won't work because all shift operations use only the lowest 5 bits of shift (in JavaScript and other C-like languages too). <<32 is equal to <<0, ie. no change.