question: public float nextFloat ( ) { return ( next ( 24 ) / 16777216f ) ; }
target:  Returns the next pseudorandom, uniformly distributed float value between 0.0 and 1.0 from this random number generator's sequence. The general contract of nextFloat is that one float value, chosen (approximately) uniformly from the range 0.0f (inclusive) to 1.0f (exclusive), is pseudorandomly generated and returned. All 224 possible float values of the form mx&nbsp2-24, where m is a positive integer less than 224 , are produced with (approximately) equal probability. The method nextFloat is implemented by class Random as follows: public float nextFloat() { return next(24) / ((float)(1 << 24)); } The hedge "approximately" is used in the foregoing description only because the next method is only approximately an unbiased source of independently chosen bits. If it were a perfect source or randomly chosen bits, then the algorithm shown would choose float values from the stated range with perfect uniformity. [In early versions of Java, the result was incorrectly calculated as: return next(30) / ((float)(1 << 30)); This might seem to be equivalent, if not better, but in fact it introduced a slight nonuniformity because of the bias in the rounding of floating-point numbers: it was slightly more likely that the low-order bit of the significand would be 0 than that it would be 1.]