Zero division Exception .
if ( $ divisor == 0 ) { echo " Cannot ▁ Divide ▁ by ▁ 0" ; echo " " ; } if ( $ dividend == 0 ) { echo $ a , " ▁ / ▁ " , $ b , " ▁ is ▁ equal ▁ to ▁ : ▁ " , 0 ; echo " " ; } if ( $ divisor == 1 ) { echo $ a , " ▁ / ▁ " , $ b , " ▁ is ▁ equal ▁ to ▁ : ▁ " , $ sign * $ dividend . " STRNEWLINE " ; echo " " ; }