simple regex in php, formatting decimal number

Question

I need to convert numbers to have .00 after them, but only if the number is an integer, or it has just 1 number after the decimal point, like so:

1.4 = 1.40
         


        

Answer 1

$num = 0.00638835;

$avg = sscanf($num,"%f")[0] /100;

echo sprintf("%.10f", $avg);

result 0.0000638835