RadixSortArrayOfIntegers.js

var extractDigit = function( a, bitMask, shiftRightAmount ) {
 var digit = (a & bitMask) >>> shiftRightAmount;	// extract the digit we are sorting based on
 return digit;
}

function radixSortLSD(_input_array) {
 var numberOfBins = 256;
 var Log2ofPowerOfTwoRadix = 8;
 var _output_array = new Array(_input_array.length);
 var count = new Array(numberOfBins);
 var _output_array_has_result = false;

 var bitMask = 255;
 var shiftRightAmount = 0;

 var startOfBin = new Array( numberOfBins );
 var endOfBin = new Array( numberOfBins );
 
 while( bitMask != 0 ) // end processing digits when all the mask bits have been processed and shifted out, leaving no bits set in the bitMask
 {
 for (var i = 0; i < numberOfBins; i++ )
 count[ i ] = 0;
 for (var _current = 0; _current < _input_array.length; _current++ ) // Scan the array and count the number of times each digit value appears - i.e. size of each bin
 count[ extractDigit( _input_array[ _current ], bitMask, shiftRightAmount ) ]++;

 startOfBin[ 0 ] = endOfBin[ 0 ] = 0;
 for( var i = 1; i < numberOfBins; i++ )
 startOfBin[ i ] = endOfBin[ i ] = startOfBin[ i - 1 ] + count[ i - 1 ];
		
 for ( var _current = 0; _current < _input_array.length; _current++ )
 _output_array[ endOfBin[ extractDigit( _input_array[ _current ], bitMask, shiftRightAmount ) ]++ ] = _input_array[ _current ];
 
 bitMask <<= Log2ofPowerOfTwoRadix;
 shiftRightAmount += Log2ofPowerOfTwoRadix;
 _output_array_has_result = !_output_array_has_result;
 
 var tmp = _input_array, _input_array = _output_array, _output_array = tmp; // swap input and output arrays
 }
 if ( _output_array_has_result )
 for ( var _current = 0; _current < _input_array.length; _current++ ) // copy from output array into the input array
 _input_array[ _current ] = _output_array[ _current ];
 
 return _input_array;
}