Why are floating point numbers printed so differently?

Question

It\'s kind of a common knowledge that (most) floating point numbers are not stored precisely (when IEEE-754 format is used). So one shouldn\'t do this:

0.3 -         


        

Answer 1

As for php, output is related to ini settings of precision:

ini_set('precision', 15);
print 0.3 - 0.2; // 0.1

ini_set('precision', 17);
print 0.3 - 0.2; //0.099999999999999978 

This may be also cause for other languages