PHP Variable returned on echo -

i using statement reason when variable 0 instead of getting output "see description" - getting output "0 see description".

why happen?

$sinput = get_field('fl_area'); $soutput = sqfeettometers($sinput);  if(trim($sinput) == "0"){echo ' see description ' ;} else {echo $soutput . ' sq. m (' . number_format($sinput ) . ' sq. f)' ;}  

to test other functions not echo'ing anything, please echo before

if(trim... 

statement. if response

0 [your echo output] see description 

you know issue is.