PHP show only significant (non-zero) decimals

Question

In PHP (using built-in functions) I\'d like to convert/format a number with decimal, so that only the non-zero decimals show. However, another requirement of mine is that if

Answer 1

My solution is to let php handle it as a number (is *1) and then treat it as a string (my example I was using percentages stored as a decimal with 2 decimal places):

printf('%s%% off', $value*1);

This outputs:

0.00  => 0% off
0.01  => 0.01% off
20.00 => 20% off
20.50 => 20.5% off